How corrupt are Britain's spies? Not only did they participate in the US torture of a British citizen; they also ensured he was kept in Guantanamo so he couldn't give evidence against them:
The post 9/11 world was just a few days old when Shaker Aamer was first imprisoned. Captured by Afghan bounty hunters while attempting to flee from Kabul with his pregnant wife and their three children, he was sold on twice, and found himself in US hands.
[...]
The interrogators that MI6 and MI5 had sent to Bagram were warned that they must not take part in the torture that was being inflicted on the inmates; all received written instructions that “we cannot be party to such ill treatment nor can we be seen to condone it”. In practice, this meant that they would remove themselves from the room before the abuses began.
After being transferred to Guantánamo, Aamer gave a statement to his lawyers in which he alleged that, despite these instructions, British intelligence officers were present while he was being severely beaten at Bagram. As a consequence of this – and because of the UK’s wider involvement in his unlawful detention and mistreatment – he is expected to embark upon legal proceedings against the British government once he returns to the UK.
Furthermore, Scotland Yard detectives investigating the British government’s involvement in rendition after 9/11 are understood to have taken a statement from him at Guantánamo.
Members of his legal team suspect that the UK’s intelligence agencies have been so alarmed by the prospect of such allegations being aired on his return to the UK that they may have fed false information about Aamer to the US authorities in order to impede that release.
So we can add "perversion of the course of justice" to their list of crimes then.
Clearly, MI6 were hoping Aamer would die in Guantanamo. But he hasn't. Instead, he's finally going to be released, after being held for 13 years without trial. And hopefully this will mean that MI6 will be both sued and prosecuted, and be held accountable for their actions.