Competence and Compellability of Witnesses in Nigeria: Who Can Testify and Who Must

Picture a murder trial where the accused person’s wife is the only witness to what happened in their home that night. The prosecution wants to call her. She does not want to testify against her husband. Can the prosecution compel her? Does she have a choice? And what happens if the accused himself wants to testify in his own defence?

These questions are answered by the rules of competence and compellability. They are distinct concepts that govern who may give evidence and who can be forced to give it. Understanding them matters not just as a theoretical exercise but as a practical question that arises in every criminal trial involving family members, persons with official status, or the accused themselves.

Competence and Compellability Defined

A competent witness is a person who is legally qualified to give evidence in a proceeding. Competence is about legal capacity. A person who lacks competence cannot give evidence even if they want to. Their testimony would be inadmissible.

A compellable witness is a person who, if they refuse to testify, can be forced by the court to do so. Compellability goes further than competence. A person may be both competent and compellable, competent but not compellable, or neither.

The general rule under section 175 of the Evidence Act 2011 is that all persons are competent witnesses. Competence is the default. Incompetence is the exception that must be established. The general rule under section 176 is that all competent witnesses are compellable. Again, non-compellability is the exception.

The exceptions are specific and important.

The General Rule: All Persons are Competent

Section 175 of the Evidence Act 2011 provides that all persons are competent witnesses unless the court considers that they are prevented from understanding the questions put to them or from giving rational answers by tender years, extreme old age, disease whether of body or mind, or any other cause of the same kind.

The standard is functional, not categorical. The court asks: can this person understand questions and give rational answers? If yes, they are competent. If not, they are incompetent.

This means that a person with a mental illness is not automatically incompetent. They are incompetent only if the illness prevents them from understanding the questions put to them and giving rational answers. A person with depression who can understand and answer questions clearly is competent. A person in an acute psychotic episode who cannot form coherent responses is not.

Similarly, a child is not automatically incompetent. Children can be competent witnesses. The test is whether the specific child understands the questions and can give rational answers. We examine child witnesses separately below.

The Accused as Witness

The accused person occupies a unique position in Nigerian criminal proceedings. Before 1946, the accused was completely incompetent to give evidence on their own behalf. They could not take the witness stand even if they wanted to.

The Evidence Act changed this. The accused is now competent but not compellable to give evidence in their own defence. Sections 180 and 181 of the Evidence Act 2011 govern this. The accused may give evidence if they choose to, but they cannot be forced to do so.

This rule is reinforced by the constitutional right to silence under section 36(11) of the 1999 Constitution, which provides that no person tried for a criminal offence shall be compelled to give evidence at trial. The right to silence in the witness box is therefore both a statutory right and a constitutional right. An understanding of how the burden and standard of proof operates in Nigeria is essential context here: the prosecution bears the burden of proving its case beyond reasonable doubt, and the accused’s non-compellability is a structural expression of that principle.

The accused who chooses to testify must do so on oath and is subject to cross-examination like any other witness. The shield in section 180(g) protects the accused who testifies from questions about other offences, prior convictions, and bad character, subject to the exceptions examined in the article on similar facts evidence. The related treatment of admissions in evidence law is also relevant where the accused has made prior statements that the prosecution seeks to use.

The accused who does not testify cannot be commented upon adversely by the prosecution. In Akpan v The State,¹ the court held that the prosecution cannot make adverse comment about the accused’s failure to testify. The related question of whether a prior confession can be used against an accused who does not testify is examined in the article on confessions under the Evidence Act 2011. However, the court itself may draw whatever inference the silence allows, depending on the circumstances.

The co-accused occupies a similarly protected position. A co-accused is competent to give evidence for the defence but is not compellable to give evidence for the prosecution.² Where a co-accused pleads guilty and the charges against them are concluded before the main trial of the remaining accused, they may then be competent and compellable as a prosecution witness, because they are no longer a co-accused but a convicted person.

Spouses: The Spousal Rule

The competence and compellability of spouses is one of the most practically significant and most examined areas of this topic.

Civil Proceedings

In civil proceedings, section 178(1) of the Evidence Act 2011 provides that the husband or wife of a party to civil proceedings is competent and compellable to give evidence on behalf of, or against, the party to the suit. Both spouses are fully competent and fully compellable in civil proceedings. There are no restrictions based on the marital relationship.

Criminal Proceedings

Criminal proceedings are far more restricted.

Section 182 of the Evidence Act 2011 provides that in criminal proceedings, the spouse of the accused person is competent but not compellable to give evidence for the prosecution or for the co-accused.

The spouse of the accused is therefore a voluntary prosecution witness only. The prosecution can call them, and they may choose to testify. But if they refuse, the prosecution cannot force them. The rationale for this non-compellability is the protection of the marital relationship and the personal dignity of the parties within it.

Section 182(1) also provides the exceptions. The spouse of the accused is competent and compellable to give evidence for the prosecution in three categories of cases:

Where the accused is charged with an offence against the person of the spouse, including offences under the relevant provisions of the Criminal Code Act dealing with assault, unlawful wounding, and sexual offences against the spouse.

Where the accused is charged with an offence against a child of the family.

Where the offence is bigamy. Under section 180 of the Evidence Act, a spouse is a competent and compellable witness on a charge of bigamy.

In Osamuyimen v The State,³ the court applied the spousal compellability exception in the context of an offence against the person of the spouse. The wife, who was the victim of the accused’s assault, was held to be compellable to testify even though she was his wife.

The principle behind the exceptions is that the very marriage that normally protects the spouse from compellability is itself the source of the offence charged. A person cannot use the marriage as a shield against giving evidence when the offence charged was committed against the very person or child the marriage is supposed to protect.

What Constitutes a Spouse?

Section 182 applies to husband and wife. For the spousal protection to apply, there must be a valid marriage at the time of the proceeding. The legal framework for marriage and divorce in Nigeria is relevant here: a person who is divorced, or whose marriage has been dissolved, is no longer a spouse and is therefore fully competent and compellable as a witness.

A cohabiting partner who is not a spouse does not benefit from section 182. There is no Nigerian statutory protection equivalent to the spousal protection for unmarried partners. This is an area where the law has not kept pace with social reality. Whether a customary law wife attracts the same protection as a statutory spouse under section 182 is a question that has not been definitively resolved by the Nigerian appellate courts.

Communications During Marriage: Section 187

Separate from compellability, section 187 of the Evidence Act 2011 protects communications made between spouses during the marriage. Even where a spouse is competent and compellable to testify, they cannot be compelled to disclose confidential communications made by one spouse to the other during the marriage. This protection survives the marriage: a divorced spouse still cannot be compelled to disclose confidential communications made during the marriage.

Children as Witnesses

Children can give evidence in Nigerian courts. The governing provisions are sections 208 and 209 of the Evidence Act 2011.

Section 208(1) provides that where in any proceeding a child of tender years is called as a witness, if the court is of the opinion that the child does not understand the nature of an oath but is possessed of sufficient intelligence to justify the reception of evidence and understands the duty of speaking the truth, the child may give evidence unsworn.

Section 209(1) provides that the unsworn evidence of a child may be acted upon even without corroboration where the court is satisfied that the evidence is reliable.

The traditional position in English law required corroboration of a child’s unsworn evidence. The Evidence Act 2011 departed from this position by allowing conviction on the uncorroborated unsworn evidence of a child, provided the court is satisfied of its reliability. This is an important departure from the old law.

The test for whether a child should give sworn or unsworn evidence is whether the child understands the nature and consequences of the oath. If the child understands that telling the truth in court is a serious obligation with consequences for lying, they may be sworn. If not, their evidence is received unsworn under the reliability test.

In Okoyomon v The State,⁴ the court applied the test for receiving a child’s evidence and confirmed that the central question is whether the child understands the duty of speaking the truth.

One analytical point worth raising is the tension between the removal of the corroboration requirement and the continuing risk that a child witness may be confused, suggestible, or subject to coaching. The 2011 Act’s departure from mandatory corroboration places heavier weight on the court’s assessment of reliability. How rigorously courts apply that reliability test in practice determines whether the departure from the old law protects or exposes vulnerable accused persons.

Persons of Unsound Mind

As established by section 175, a person of unsound mind is not automatically incompetent. Competence depends on whether the person can understand questions put to them and give rational answers.

The court may, in appropriate cases, receive the evidence of a person suffering from mental illness if the person is lucid at the time of giving evidence and can understand and respond to questions rationally. Psychiatric evidence may be relevant to help the court assess the person’s condition.

The Privilege Against Self-Incrimination: Section 183

A category that is distinct from competence and compellability, but which frequently arises in the same discussions, is the privilege against self-incrimination under section 183 of the Evidence Act 2011. Section 183 provides that no person shall be compelled to answer any question if the answer to it would, in the opinion of the court, tend to expose the witness or the spouse of the witness to any criminal charge, penalty, or forfeiture.

This privilege belongs to any witness, not only the accused. A third-party witness who is competent and compellable may nevertheless refuse to answer a specific question if the answer would incriminate them. The court must be satisfied that the risk of incrimination is real, not speculative.

Section 183 contains important provisos. A person charged with an offence who chooses to testify under section 180 may be asked, and is bound to answer, any question in cross-examination that tends to incriminate them as to the offence charged. Having chosen to testify, the accused cannot selectively invoke section 183 to avoid questions about the offence itself. The privilege in that context applies to other offences not charged, not to the offence before the court.

The self-incrimination privilege in section 183 should not be confused with the accused’s general non-compellability under sections 180 and 181. Non-compellability means the accused cannot be required to enter the witness box at all. The section 183 privilege is a narrower protection available to any witness once in the box.

Diplomatic Agents and International Officials

A category not covered in section 175 but of practical importance is the non-compellability of diplomatic agents and certain international officials. By virtue of section 1(1) of the Diplomatic Immunities and Privileges Act 1962, foreign envoys, consular officers, and members of their families and official staff are accorded immunity from suit and legal process in Nigeria. They cannot be summoned to court as witnesses.

Similar protection is extended to High Commissioners from Commonwealth countries under section 3 of the Act, and to officials of certain international organisations whose names are published in the official gazette under section 11.

These immunities can be waived. The waiver must come from the diplomat’s home government, not from the diplomat personally. A diplomat who voluntarily appears as a witness in Nigerian proceedings does so either on the basis of a waiver by their government or by choice, and their testimony is then admissible. The key case on the limits of diplomatic immunity in the commercial context is Zabusky v Israeli Aircraft Industries, where the court held that immunity does not cover commercial activities undertaken outside the diplomat’s official capacity.

Bankers: Section 177

Section 177 of the Evidence Act 2011 provides that a banker or officer of a financial institution is not compellable to produce the books of the institution or to appear as a witness to the contents of those books in any proceeding to which the institution is not a party, if it appears that production of the books or giving of evidence as to their contents would be prejudicial to the institution. The court may, however, make an order for production where it is in the interests of justice to do so.

This is a pragmatic provision. Banks are frequent custodians of records relevant to litigation between third parties. Requiring bank officers to appear and give oral evidence in every such proceeding would be disruptive and expensive. Section 177 therefore protects banks from compulsory production unless the court specifically orders it.

Bankers’ books as secondary evidence are admissible under section 89(h) of the Evidence Act through a separate route that does not require compulsory production of the bank officer as a witness. The section 177 protection relates to compelling personal attendance and production of the original books, not to the admissibility of entries under the banker’s books provision.

Persons with Interests

The old common law excluded certain persons from giving evidence because of their interest in the proceedings. Parties to a suit, their spouses, and persons convicted of crimes were incompetent witnesses at common law. The Evidence Act 2011 has swept away these common law disqualifications. Section 175 contains no disqualification based on interest, criminal conviction, or personal stake in the outcome.

The fact that a witness has an interest in the outcome of the case goes to weight, not competence. The court can believe or disbelieve an interested witness based on an assessment of their credibility and the consistency of their evidence with other facts.

The President, Vice President, Governors, and Deputy Governors

A common error in examination answers is to attribute the non-compellability of the President to the Evidence Act. The correct authority is section 308 of the Constitution of the Federal Republic of Nigeria 1999.

Section 308 provides that no civil or criminal proceedings shall be instituted or continued against a person to whom the section applies during their period of office; they shall not be arrested or imprisoned; and no process of any court requiring or compelling their appearance shall be applied for or issued. Section 308(3) specifies that the section applies to the President, Vice President, Governor, and Deputy Governor.

The President and other persons covered by section 308 are therefore not compellable to attend as witnesses while they hold office. The immunity is not permanent: it applies only during the period of office. A former President, former Governor, or former Deputy Governor is fully competent and compellable like any other citizen once they leave office.

Two points require attention. First, section 308 immunity, unlike the spousal non-compellability protection, is constitutionally grounded and absolute in its terms during the period of office. The courts have confirmed that section 308 is mandatory: in Fawehinmi v IGP, the court noted that section 308 precludes both criminal proceedings and the exercise of investigative processes against covered officeholders during their tenure. Second, the immunity does not protect acts done after the period of office, nor does it protect the officeholder’s associates or officials merely because of their connection to the covered person.

State Governors and their Deputies are expressly covered by section 308(3). This is not a matter of interpretation: the Constitution expressly includes them. The common student mistake of treating only the President as constitutionally protected from compellability, while treating the Governor’s protection as uncertain or dependent on common law, should be avoided.

The Constitutional Dimension

The competence and compellability rules connect directly to section 36 of the 1999 Constitution.

Section 36(11) provides that no person tried for a criminal offence shall be compelled to give evidence at trial. This is the constitutional foundation of the accused’s non-compellability as a witness.

Section 36(6)(d) provides that an accused person is entitled to examine witnesses called by the prosecution. This right to cross-examine means that competence and compellability rules must not be manipulated in ways that deprive the accused of the opportunity to confront witnesses against them. If a prosecution witness claims non-compellability in circumstances where the Evidence Act does not actually protect them, and the court accepts that claim, the accused may be deprived of the constitutional right to cross-examine.

A Quick Reference Table

Key Cases

Osamuyimen v The State The court applied the spousal compellability exception where the accused was charged with an offence against the person of the spouse, holding that the spouse was compellable to give evidence for the prosecution.

Akpan v The State (2008) 14 NWLR (Pt. 1107) 241 The court held that the prosecution cannot make adverse comment about the accused’s failure to testify. The right to silence under section 36(11) of the Constitution means silence cannot be used against the accused.

Okoyomon v The State (1973) 1 SC 41 The court applied the test for receiving a child’s evidence, confirming that the central question is whether the child understands the duty of speaking the truth and possesses sufficient intelligence.

Fawehinmi v IGP The court confirmed that section 308 of the 1999 Constitution prevents both criminal proceedings and investigative processes against covered officeholders during their tenure of office.

Zabusky v Israeli Aircraft Industries The court held that diplomatic immunity does not extend to commercial activities undertaken outside the diplomat’s official functions.

Isiyaku Mohammed v Kano Native Authority (1968) 1 All NLR 424 The Supreme Court held that the test of fair hearing is the impression of a reasonable observer of the proceedings. This applies to the manner in which witnesses are called and examined.

Problem Question Framework

When a problem question raises questions about whether a witness can or must give evidence, apply this framework.

First, establish competence. Apply the general rule that all persons are competent under section 175. Then check whether any specific ground of incompetence applies: is the person unable to understand questions or give rational answers due to age, mental illness, or other cause?

Second, establish compellability. Apply the general rule that competent witnesses are compellable. Then check whether any specific exemption applies: is the witness the accused? A spouse of the accused in criminal proceedings? The President, Vice President, Governor, or Deputy Governor during tenure? A diplomatic agent? A banker being asked to produce institution books?

Third, for spousal witnesses in criminal proceedings, determine whether any of the section 182(1) exceptions apply: offence against the person of the spouse, offence against a child of the family, or bigamy.

Fourth, for child witnesses, determine whether the child understands the nature of an oath (sworn evidence) or merely understands the duty to speak the truth (unsworn evidence under section 209). Note that unsworn evidence from a child can ground a conviction without corroboration if the court is satisfied of its reliability.

Fifth, check whether section 183 self-incrimination privilege is engaged. Even a competent and compellable witness may refuse to answer a specific question if the answer would tend to incriminate them.

Sixth, engage the constitutional dimension. If the accused is being pressured to testify or if a witness is being wrongly classified as non-compellable in ways that deny the accused the opportunity to cross-examine, identify the constitutional right engaged under section 36.

Seventh, for the President, Vice President, Governor, or Deputy Governor, apply section 308 of the Constitution, not the Evidence Act. The protection is constitutional, not statutory, and covers all four categories of officeholder expressly.

Common Student Mistakes

The first mistake is conflating competence and compellability. A witness who is competent may still refuse to testify if they are not compellable. The two concepts must always be addressed separately.

The second mistake is treating the accused as incompetent to give evidence. The accused is competent but not compellable. They have the right to choose whether to testify.

The third mistake is attributing the President’s non-compellability to section 182(2) of the Evidence Act. The correct authority is section 308 of the 1999 Constitution. Section 182 of the Evidence Act governs spousal compellability. This is a frequently repeated error in examination answers.

The fourth mistake is failing to extend the constitutional protection to Governors and Deputy Governors. Section 308(3) expressly covers them alongside the President and Vice President. Treating only the President as constitutionally protected is an incomplete answer.

The fifth mistake is applying the full spousal protection in civil proceedings. Section 182 applies only in criminal proceedings. In civil proceedings, both spouses are fully competent and compellable.

The sixth mistake is thinking all children must give unsworn evidence. Children who understand the nature of an oath can give sworn evidence. Only children who fail the oath understanding test give unsworn evidence under section 209.

The seventh mistake is confusing section 183 (self-incrimination privilege) with the spousal non-compellability provisions. Section 183 is a separate privilege that applies to any witness who would be incriminated by a specific answer, not to spousal non-compellability.

The eighth mistake is ignoring diplomatic immunity and banker non-compellability as categories in problem answers involving those persons.

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Footnotes

¹ Akpan v The State (2008) 14 NWLR (Pt. 1107) 241.

² Evidence Act 2011, s 180.

³ Osamuyimen v The State (unreported, applied in Faculty of Law materials, University of Ibadan 2021).

⁴ Okoyomon v The State (1973) 1 SC 41.