Shaker Aamer, the last British resident to be held at the US prison camp in the Guantanamo Bay navy station in Cuba, has been freed after 13 years in detention, British foreign secretary Philip Hammond confirmed on Friday.
Aamer, a Saudi national who is married to a British national, was never charged with any crime and had been cleared for release by US authorities in 2007 but was not freed.
Last month Britain said Mr Aamer was due to be released but no date was specified.
“I can confirm that he is on his way back to the UK now and he will arrive in Britain later today,” Mr Hammond said.
Mr Aamer moved to Britain in 1996 and was in Afghanistan doing voluntary work for an Islamic charity when he was captured by Afghan Northern Alliance forces in 2001 and handed to the US military, according to rights group Reprieve.
He was moved to Guantanamo in 2002.
Amnesty International's UK director Kate Allen said:"After so many twists and turns in this appalling case, we won't really believe that Shaker Aamer is actually being returned to the UK until his plane touches down on British soil.
“We should remember what a terrible travesty of justice this case has been, and that having been held in intolerable circumstances for nearly 14 years Mr Aamer will need to time to readjust to his freedom.”
Mr Aamer has said he was originally seized by bounty hunters while working as a charity worker in Afghanistan in 2001 shortly after the 9/11 attacks.
He was handed over to US forces and in February 2002 he was transferred to Guantanamo Bay and accused of aiding al-Qaeda.
During his time in captivity, his lawyers said he was subjected to torture, with beatings and sleep deprivation, and held in solitary confinement for 360 days. In 2005, he lost half his body weight during a hunger strike.
He was described in US military files obtained by the WikiLeaks website as a "close associate of Osama bin Laden" who fought in the battle of Tora Bora. But in 2007 the allegations against him were dropped and he was cleared for release.
Despite a formal request by then foreign secretary David Miliband, American authorities refused to allow him to go.
In letters, Mr Aamer said he was not sure if he would know how to respond to his name after being referred to as 239 – his prison number – for more than a decade.
Wecoming the news, UK Labour leader Jeremy Corbyn said, "Now that Shaker has been released, the scandal of the Guantanamo detention camp itself must be brought to an end. I hope that Shaker and his family will now be given the time and space to rebuild their lives."
Guantanamo Bay is a US detention centre in the south-eastern tip of Cuba. The military prison was set up in the wake of the 9/11 attacks on the World Trade Center in New York to detain what the US government called “enemy combatants”.
The first 20 detainees were transferred to the facility on January 11th 2002, and a total of 780 men have been held since then – the vast majority without charge or criminal trial. Human rights groups and political leaders across the world have criticised Guantanamo and called for its closure since allegations of torture and abuse were unearthed.
Reports from current and former inmates included references to sleep deprivation, beatings and solitary confinement. Until 2009, the American government strenuously denied that torture had occurred at Guantanamo.
When he first took office, US president Barack Obama pledged to close the controversial facility by January 2010. However, his efforts have been stymied by opponents in Congress for years.
A White House spokesman said in June that the US administration is in the "final stages" of drafting its latest plan to close the prison.
There are still over 100 inmates being held at the facility.