Reprieve's Director, Clive Stafford Smith, said: "Enforced disappearance is a crime most associated with ruthless South American dictatorships, yet here we have the U.S. and British governments embroiled in the same dirty deeds. Kidnapping is a crime in anyone's language, and it is about time that powerful governments are held to account for their crime against Mustafa Nasser."

Diego Garcia has featured prominently in at least two other current cases. In one, Reprieve is suing the U.K. government on behalf of British resident Binyam Mohamed, a recently released Guantanamo detainee, for allowing the island's airbase to be used to facilitate Mohammed's "rendition," by landing to refuel.

Mohammed was first rendered from Pakistan to prison in Morocco, and finally to Guantanamo. The group claims he was tortured in all three locations.

David Miliband, the British Foreign Secretary, has argued before the U.K. High Court that it must suppress evidence of torture because the U.S. has t