But the handing over of the investigation, initiated by judge Sir Peter Gibson, to a group of MPs has prompted fears of a "whitewash" among campaigners, given the Commons Intelligence and Security Committee (ISC), which will take up the probe, had previously concluded Britain was not complicit in illegal activity.
It follows claims airports at Wick, Aberdeen and Inverness were used in the rendition of terrorist suspects by the CIA. Documents seen by the Gibson inquiry showed British agents were told in 2002 that there was "no obligation to intervene" if they came across apparent breaches of the Geneva Convention.
A minute appeared to show the growing doubts of the then Prime Minister Tony Blair about the activities of American allies as he admitted how he was "initially sceptical about claims of torture" against detainees but said he had to make clear to the US it would be totally unacceptable. The Prime Minister said he was determined to "clear things up" to "restore Britain's moral leadership in the world".
But David Cameron's judge-led inquiry was halted after the launch of police investigations relating to detainees allegedly transported illegally to Libya.
Ken Clarke, the Minister Without Portfolio, said it would be wrong to ask a judge to take forward an inquiry which could compromise a criminal probe.
Shami Chakrabarti, of human rights group Liberty, said: "The 'judge-led inquiry' that never was is shut down and investigating kidnap and torture in freedom's name will be left to a watchdog that never barks and which exonerated the spooks six years ago."