Speaking for the first time since the US Government announced that he would finally be released from the notorious detention camp, Shaker Aamer, 46, today makes a series of astonishing new claims. It can be revealed that:
• Despite his imminent freedom, he says he is still being subjected to brutal physical abuse by his captors
• He is on hunger strike in protest at an assault by guards, who, he says, forced him to give blood samples
• Mr Aamer has warned his wife and four children in London - including a son who was born after his imprisonment - that he may still not make it out alive from the military prison, where he has been held without charge since he was captured as an alleged Al Qaeda suspect in the wake of 9/11
Mr Aamer said: "I know there are people who do not want me ever to see the sun again. It means nothing that they have signed papers, as anything can happen before I get out. So if I die, it will be the full responsibility of the Americans."
He added that he had many people to thank, including The Mail on Sunday "which has been campaigning for my release for years".
Last night senior Conservative MP David Davis said this newspaper's revelations "massively strengthened" the case for an independent inquiry into Britain's alleged involvement in the systematic torture of terror suspects.
He said: "The time has come for the Government to face up to Britain's role in torture and rendition.
"Only by dealing with it can we restore our nation's honour and integrity."
The Mail on Sunday first exposed the horrors of Guantanamo Bay to a shocked world in 2002 and has long been campaigning for Mr Aamer's release. On Thursday he was able to talk by telephone to lawyer Clive Stafford Smith, the head of his legal team, and a transcript of that conversation provides Mr Aamer's first account of his feelings at being told he will be allowed home.
This newspaper has also obtained a draft of a 24,000-word statement he provided to Metropolitan Police detectives two years ago, giving the most detailed account ever of his ordeal. The Met was investigating UK complicity in rendition and torture.
Mr Aamer told detectives that he was "abused by the US military from the day I arrived" at Bagram air base in Afghanistan in December 2001.
He says he had travelled to the country earlier that year from Britain to work for a charity, but was kidnapped by villagers and sold to the Americans.
He assumed they would release him but, instead, the military considered him a senior figure in Al Qaeda who knew Osama Bin Laden, and was later described as a "reported recruiter, financier and facilitator with a history of participating in jihadist combat."
Despite these allegations - which he categorically denies - Mr Aamer was never charged with any crime and never faced any court.
He tells how he was held in a freezing cold aircraft hangar during the bitter Afghan winter and claims a British intelligence officer was present during interrogations when his head was repeatedly beaten into a wall by the Americans.
And he says he was grilled by two British spies about his time in London, where he had married a British woman and worked as a translator.
On Valentine's Day 2002 - the day his fourth child was born - Mr Aamer says he was stripped naked, given the infamous Guantanamo orange jumpsuit and tightly restrained before being flown to the US military prison on Cuba.
He was first cleared for release in 2007 and again two years later. Finally, on September 25 this year, the US announced he would be released within weeks.
Mr Stafford Smith said yesterday: "It may be that no one has suffered more at Guantanamo than Shaker Aamer, because he stood up for his rights and the rights of others - and for this he has constantly been punished.
"Mr Cameron's government likes to harp on about the need for people to take responsibility for their actions. Surely Britain must now accept its responsibility for this."