In 2004, Britain kidnapped Sami al-Saadi in Hong Kong and illegally rendered him to Libya. The same year, they helped the CIA do the same to Abdul Hakim Belhaj and his family in Thailand. Both men were tortured by the Libyan regime, and it is clear that MI6 knew this would happen. As a result, MI6 is being investigated by the police for conspiracy to torture.
But the British rendition of these men wasn't just a crime - it was also a mistake:
A secret UK-Libyan rendition programme in which two Libyan opposition leaders were kidnapped and flown to Tripoli along with their families had the effect of strengthening al-Qaida, according to an assessment by the UK security service, MI5.
Prior to their kidnap, Abdel Hakim Belhaj and Sami al-Saadi had ensured that their organisation, the Libyan Islamic Fighting Group (LIFG), focused on the overthrow of Colonel Gaddafi, the classified assessment says. Once handed over to the Gaddafi regime, their places at the head of the LIFG were taken by others who wanted to bring the group closer to al-Qaida.
Two years after MI5 made this assessment, Libi announced the LIFG had formally joined forces with al-Qaida. He became a leading member of the merged organisation and is believed to have orchestrated a series of suicide bomb attacks across Afghanistan, including one in 2007 that killed 23 people at Bagram airfield north of Kabul during a visit by then US vice-president Dick Cheney. Libi was killed in a drone strike the following year.
Naturally, the British spies kept quiet about their terrible, criminal mistake. The only reason we know about it is because they gave a copy to Gaddafi's torturers, which was found after their overthrow. Also in those documents was a list of 1600 questions the British wanted the Libyan "interview team" to ask Belhaj and Saadi while they were being tortured. That should be of great interest to the police.