R v Taaffe [1984] AC 539
Drug importation – Requirement of actual knowledge of drugs
Facts
Paul Desmond Taafe (T) was enlisted by a third party in Holland to import cannabis into England, which was prohibited to import under the Misuse of Drugs Act 1971. T, however, had mistakenly believed the substance to be currency, which T had believed was prohibited to import but was in fact not. T was charged under section 170(2) of the Customs and Excise Management Act 1979 (1979 Act) of having been knowingly concerned in the fraudulent evasion of the prohibition on the importation of cannabis. T was convicted and appealed.
Issues
The issue in question was whether T’s version of events in which he had erroneously believed the prohibited substance to be currency, if accepted by the jury, should entitle him to be acquitted.
Held
‘Knowingly concerned’ under section 170(2) of the 1979 Act had to be read as actual knowledge that the substance in question was one the importation of which is prohibited. T was not knowingly concerned in the fraudulent evasion of the prohibition on the importation of cannabis when he mistakenly believed that the substance he was importing was currency. For an offence of which the ingredients are the defendant’s state of mind and knowledge, the defendant must be judged on the facts as he believed them to be. T’s mens rea for the impossible offence of smuggling currency could not be imported to the smuggling of drugs. The Court of Appeal allowed T’s appeal and his conviction was quashed. The House of Lords dismissed the prosecution’s appeal.
Updated 20 March 2026
This case summary remains legally accurate. R v Taaffe [1984] AC 539 continues to be good law and is regularly cited in discussions of mistake, mens rea, and the requirements of section 170(2) of the Customs and Excise Management Act 1979. The Misuse of Drugs Act 1971 remains in force, as does section 170(2) of the 1979 Act, though readers should note that the broader legislative landscape governing drug offences and customs enforcement has been supplemented over the years (including by the Psychoactive Substances Act 2016 for certain substances). Nothing in subsequent case law or statute has undermined the core principle established in Taaffe that a defendant must be judged on the facts as he believed them to be for offences requiring actual knowledge. The article is suitable for use as a case summary on this point.
