Shaker Aamer: 'British agent witnessed my beating'
Shaker Aamer was the last British resident of Guantanamo Bay. He was held without trial for more than 13 years.
Aamer was held over extremely serious claims - that he had led a Taliban unit and met Osama Bin Laden. The US military classified him as a threat, but he was never charged.
His lawyers say the case against him came from unreliable allegations extracted during torture, and that his treatment at the US military base in Cuba raises serious questions about the legality and morality of the so-called war on terror.
He told the BBC's Victoria Derbyshire that he believes a British official witnessed him being beaten in Afghanistan.
Mark Easton reports.
In a statement to the BBC the government said it "stands firmly against torture and cruel, inhumane and degrading treatment or punishment".
The US Department of Defense said: The DOD does not tolerate the abuse of detainees. All credible allegations of abuse are thoroughly investigated, and appropriate disciplinary action is taken when those allegations are substantiated. We take such matters very seriously.
13 Dec 2015