A FLURRY of letters between the British Foreign Office and the US State Department has revealed that Washington did threaten to withdraw intelligence-sharing with Britain if documents related to the alleged torture of a British terrorism detainee in Guantanamo Bay were made public.

The High Court in London said on Wednesday the Foreign Office had refused to allow the torture documents to be revealed because of a "threat" from Washington to stop sharing intelligence with Britain.

Close but not too close: British Foreign Secretary David Miliband met US Secretary of State Hillary Clinton earlier this week. Credit:AFP

The US warning, related to the case of British detainee Binyam Mohamed, was promptly denied by British Foreign Secretary David Miliband, who insisted that there had been no threat from the US to "break off intelligence co-operation".

But on Thursday night British broadcaster Channel 4 revealed that a letter dated August 21, 2008, from the US State Department, stated the consequences if a British court published American documents on the capture and interrogation of Mohamed.