Chung Chi Cheung v R  AC 167
INTERNATIONAL LAW – FOREIGN ARMED PUBLIC SHIP – WAIVER OF IMMUNITY – TERRIRTORIAL JURISDICTION
The appellant (C), a British subject, who was cabin boy on board a Chinese Maritime Customs cruiser - a foreign armed public ship - killed by shooting the captain of the vessel, also a British subject in the service of the Chinese Government, while the vessel was in the territorial waters of Hong Kong. C was arrested in Hong Kong and, with extradition proceedings instituted by the Chinese authorities having failed on the ground that the appellant was a British national, C was rearrested and charged with murder before the British court. He was ultimately convicted and sentenced to death, the acting chief officer and three of the crew of the Chinese cruiser having given evidence for the prosecution at the trial. C brought an appeal, alleging that the local British Court had no jurisdiction to try him.
Whether, in the particular circumstances of the case, the jurisdiction of the British Court had been validly exercised; whether the crew of a foreign public ship enjoy immunity from prosecution by virtue of such vessels being an extension of the territory to which they belong; whether, in any event, immunity from prosecution had been waived by the Chinese Government.
A public armed ship in foreign territorial waters is not to be treated as a part of the territory of its own nation. The immunities which are generally accorded to a foreign armed public ship and its crew do not depend upon an objective exterritoriality but rather upon an implication of domestic law, and flow from a waiver by a sovereign state of its full territorial jurisdiction. These immunities are therefore conditional and can themselves be waived by the home nation. As the Chinese government did not register a diplomatic request for the surrender of the appellant after the failure of the extradition proceedings, and as members of their service were subsequently granted permission to give evidence before the British Court in aid of the prosecution, the jurisdiction of the British Court had been validly exercised.