The Tort of Conspiracy in Nigerian Law: Elements, Defences, and Remedies

You are a successful frozen fish trader in Mushin Market. Three of your competitors, who together control the supply chain in your area, decide privately that your growing market share threatens them. They agree, informally but deliberately, to collectively refuse you supply. They have not lied to you. They have not threatened you. Each of them, individually, has done nothing unlawful. But together, their combination brings your business to its knees.

This is the scenario that sits at the heart of the tort of conspiracy, and it raises one of the more intellectually interesting questions in Nigerian tort law: when does the combination of otherwise lawful acts become an unlawful wrong?

What the Tort Is

The tort of conspiracy is an agreement or combination of two or more persons to injure the business of another, through means that are either unlawful or, even if lawful, pursued with the predominant purpose of causing harm rather than advancing the defendants’ own legitimate interests, which combination causes actual damage to that business. The cases of Sorrell v Smith and Crofter Hand Woven Harris Tweed Co. Ltd v Veitch remain foundational to the modern law.

It is worth pausing immediately on what makes this tort conceptually distinctive. Other business torts in the same family, namely inducing breach of contract, intimidation, and the deceit considered separately in our article on The Tort of Deceit, each turn on a specific unlawful act by the defendant: inducing someone to break a contract, threatening unlawful harm to compel conduct, or making a fraudulent misstatement. Conspiracy is different because the unlawfulness can arise from the combination itself, even where no individual act by any defendant would be actionable standing alone. That is its unique character and also its limitation: the courts have been careful not to extend it too far, conscious that combinations of persons acting together are often the basis of legitimate commerce, trade unionism, and collective bargaining.

The economic torts also share a relationship with the contractual doctrine of restraint of trade. Where businesses combine to exclude a competitor from a market, there may be overlap between the tort of conspiracy, the statutory competition law framework under the Federal Competition and Consumer Protection Act 2018, and the common law restraint of trade doctrine that operates in Nigerian contract law. The tort of conspiracy provides a damages remedy; competition law provides administrative enforcement. A claimant with strong facts may legitimately pursue both avenues.

The Two Categories of Conspiracy

Nigerian law, following English common law, recognises two forms of actionable conspiracy.

The first is conspiracy to injure, sometimes called simple conspiracy. Here the defendants combine to pursue a purpose whose predominant aim is the injury of the plaintiff, even if the means they employ are otherwise lawful. The critical test is purpose. Where the court accepts that the defendants’ real predominant motive was the advancement of their own legitimate trade interests, and that the plaintiff’s harm was incidental, the defence of legitimate purpose succeeds. In Crofter Hand Woven Harris Tweed Co. Ltd v Veitch, dock workers who imposed an embargo on Harris Tweed not made on the island of Lewis were held to have acted in furtherance of their legitimate trade interests as workers, not with the predominant purpose of injuring the plaintiffs. The action failed.

The second is unlawful means conspiracy, which arises where the defendants combine to use unlawful means, whether or not their purpose was primarily to harm the plaintiff. Where the means are unlawful, such as fraud, intimidation, inducing breach of contract, or any other recognised tort or crime, the combination is actionable without the further need to establish that injuring the plaintiff was the predominant purpose. This form of conspiracy therefore has a closer relationship with intimidation (which is the use of unlawful threats to compel conduct) and inducing breach of contract (which is the deliberate interference with contractual relationships). All three are economic torts, all three protect business interests from deliberate external interference, and in practice a single fact pattern will often disclose multiple potential claims.

Two Essential Elements

There must be a combination of at least two persons, working together towards a shared purpose. The combination need not be formalised in writing. An informal understanding, coordinated conduct, or a pattern of behaviour from which a joint purpose can be inferred is sufficient. In the Nigerian context, combinations commonly arise between competing market traders, between employers acting jointly in a lockout, between trade union officers acting together, and between companies operating as a cartel.

The plaintiff must prove that the purpose of the combination was to inflict damage on his business. This is the heart of simple conspiracy and the element most difficult to establish. It requires more than showing that harm occurred; it requires showing that harm was the point. Evidence of communications between the conspirators, the timing of their acts, their pattern of conduct before and after the harm, and the absence of any plausible legitimate business explanation for their behaviour are all relevant.

Damage

Conspiracy is not actionable without proof of actual damage. A trader who can prove the combination but cannot demonstrate that it caused real, quantifiable harm to his business will fail. This is a significant practical constraint. The requirement of damage applies whether the claim is in simple conspiracy or unlawful means conspiracy.

The Defence of Legitimate Purpose

A combination made in furtherance of the legitimate trade interests of the defendants is not a conspiracy even where the plaintiff is harmed. Once legitimate purpose is established, the defence is complete, and it does not matter that the harm caused to the plaintiff is disproportionate to the benefit secured. In Scale Ballroom (Wolverhampton) Ltd v Ratcliffe, a trade union combination that imposed economic harm on the plaintiff was held justified because the members were pursuing genuine employment interests.

It is worth noting what is not a legitimate purpose: pure spite, the destruction of a competitor without any proportionate benefit to the defendants themselves, and the use of market power to harm a rival as an end in itself rather than as a means of advancing the defendants’ own business.

Conspiracy and Criminal Conspiracy Distinguished

The civil tort and the criminal offence share a name but serve different masters. Civil conspiracy is pursued by the private plaintiff for damages. Criminal conspiracy, addressed in our article on Conspiracy in Nigerian Criminal Law, is prosecuted by the state for punishment. The standard of proof differs: balance of probabilities in civil proceedings, proof beyond reasonable doubt in criminal proceedings. Proof of actual damage is required in the civil tort but not always in the criminal offence. Both may be available simultaneously where the same combination satisfies both the tortious and criminal definitions.

Remedies

Damages compensate the plaintiff for all losses flowing from the combination, including lost profits, lost contracts, and damage to goodwill. Where the combination is ongoing, an injunction may be sought to restrain the defendants from continuing. An interim injunction is available where damages alone would be an inadequate remedy and there is a serious question to be tried.

Frequently Asked Questions

Can I sue my competitors for conspiring to damage my business in Nigeria? Yes, if you can prove the combination, that its predominant purpose was to injure you rather than advance the defendants’ legitimate interests, and that you suffered actual business damage. The challenge is proving purpose, which typically requires evidence of the defendants’ internal communications or coordinated conduct.

Is a trade union strike a conspiracy? Not necessarily. Trade unions enjoy statutory immunities for action taken in furtherance of a legitimate trade dispute. A strike genuinely aimed at improving working conditions is protected. A coordinated action with no genuine industrial purpose and designed only to harm a named employer may not be.

What is the difference between conspiracy and inducing breach of contract? Inducing breach requires a specific contractual relationship that the defendant has interfered with by persuading one party to break it. Conspiracy requires only a combination of persons with a harmful purpose. Both are economic torts and may arise from the same facts.

Conclusion

The tort of conspiracy is the law’s response to coordinated economic warfare. It acknowledges what every market participant in Nigeria already knows: that harm can be inflicted not only by a single wrongdoer acting alone but by a group of persons combining their resources, relationships, and market power to destroy a target. The law’s restraint in confining the tort to cases of improper purpose or unlawful means reflects a considered balance: combinations are often the legitimate basis of commerce and collective action, and the law does not penalise them merely because they harm a competitor. But where the combination exists to destroy rather than to compete, the law has a remedy.

For the full picture of intentional torts in Nigerian law, read our articles on Defamation in Nigerian Law, Malicious Prosecution, and The Tort of Deceit in Nigerian Law.

References Kodilinye and Aluko, The Nigerian Law of Torts (Spectrum Books, Lagos, 1995) Ese Malemi, Law of Tort (Princeton Publishing Company, 2013) Otuturu, “Trade Unions and Economic Torts” (2010) Vol 4, No 4 Labour Law Review NJLIR 49 Trade Unions Act Cap T14 LFN 2004 Federal Competition and Consumer Protection Act 2018 (Nigeria)