Chan v The Queen

Chan appealed to the High Court of Australia against his conviction for conspiracy to import a commercial quantity of heroin. The prosecution alleged that Chan was part of a conspiracy to import heroin from Thailand into Australia. The central issue at trial was whether Chan had been a knowing participant in the conspiracy.

The High Court was required to determine whether the trial judge had erred in admitting certain evidence against Chan, specifically evidence of conversations between co-conspirators that occurred after Chan had allegedly withdrawn from the conspiracy. The appeal also raised questions about the proper application of the principles governing the admissibility of evidence in conspiracy cases, particularly concerning the distinction between evidence that proves the existence of a conspiracy and evidence that proves a particular accused's participation in it.

McHugh and Kirby JJ, in separate judgments, allowed the appeal. Their Honours held that the trial judge had erred in admitting the post-withdrawal conversations as evidence against Chan. They reasoned that once a person has withdrawn from a conspiracy, statements made by other conspirators are generally not admissible against that person as they do not reflect the common intention of the conspirators at the time the statements were made. The court emphasised that the prosecution must prove beyond reasonable doubt that the accused was a member of the conspiracy at the time the alleged conspiratorial acts or statements were made.

The High Court quashed Chan's conviction and ordered a new trial.