Yip-Chiu-Cheung v The Queen (1994) 2 All E.R. 924
Conspiracy – Criminal Attempts – Drug Trafficking – Mens Rea
Facts
The defendant entered into an agreement with an undercover narcotics officer in a hotel in Hong Kong. The agreement was that the defendant was to give the officer 5kg of heroin to be smuggled into Australia. In return, the officer was to receive US$16,000. The police officer never flew into Australia and in fact never met the defendant because of a cancelled flight. The defendant was arrested and charged with conspiracy to traffic drugs contrary to Hong Kong’s penal code. He was convicted and appealed on the ground that in law there was in fact no conspiracy because the police officer never had the requisite mens rea of intent to traffic the drugs as the officer had been in contact at all times with the authorities in both Hong Kong and in Australia.
Issues
Did the defendant commit the crime of conspiracy? Whether the undercover police officer had the requisite mens rea to commit the offence of trafficking? Whether both parties to a ‘conspiracy’ require real intent to carry out the crime?
Decision/Outcome
The defendant’s appeal was dismissed. Because the undercover agent had not intended to prevent the heroin being smuggled, but had intended to arrest the defendant and others after the smuggling had occurred, a conspiracy existed. Both parties were guilty, notwithstanding that the authorities were aware of what was occurring and that they did not intend to stop it. The undercover agent of course would not be prosecuted for the offense. The fact that the authorities did not intervene or prevent the offense occurring did not prevent it being a conspiracy.
Updated 20 March 2026
This case note accurately summarises the Privy Council decision in Yip Chiu-cheung v R [1994] 2 All ER 924. The core legal principle — that an undercover police officer can provide the necessary mens rea for a conspiracy where he genuinely intends to carry out the unlawful act (even if his purpose is ultimately to facilitate arrest) — remains good law in England and Wales and has not been overturned.
Students should note that the law of conspiracy in England and Wales is now primarily governed by the Criminal Law Act 1977 (as amended), and the case was decided on appeal from Hong Kong by the Privy Council rather than by an English court. However, the principle has been adopted and applied in English law. The decision is consistent with the general approach to conspiracy mens rea confirmed in subsequent English authorities. There are no significant statutory changes or later cases that undermine the principle as described in this article.
