Claims UK spy agencies aided CIA torture after 9/11 to be heard in court

The UK's decades-long efforts to suppress details of its involvement in the CIA's post-9/11 torture programme will face an "unprecedented" challenge this week as two cases come before a secretive court.

- Harry Davies

The cases, filed by two prisoners held at the US military prison at Guantanamo Bay, will be heard across a rare four-day trial at the investigatory powers tribunal (IPT), which has been investigating claims that the UK's intelligence agencies were complicit in their mistreatment.

Starting today, the trial will place a spotlight on what is considered one of British intelligence's darkest chapters, reviving longstanding questions about the extent of the UK's involvement in the CIA's kidnapping and detention of terrorism suspects in a global network of secret prisons known as black sites.

Six years ago, ministers shelved a judicial inquiry into alleged UK complicity, which David Cameron - the prime minister who ordered it - had said was necessary because: "The longer these questions remain unanswered, the bigger the stain on our reputation as a country."

The claims before the IPT have been brought by Mustafa al-Hawsawi, who is accused by the US of aiding the hijackers behind the 9/11 terrorist attacks, and Abd al-Rahim al-Nashiri, who is alleged to have plotted al-Qaida's bombing of a US Navy ship in 2000.