AFP/London

The last British resident in Guantanamo Bay was on Friday returning to London having been released after spending over 13 years at the military prison in Cuba, Britain's foreign minister said.

"I can confirm that he is on his way back to the UK now and he will arrive in Britain later today," Philip Hammond said.

The US accused 46-year-old Saudi national Shaker Aamer of acting as a recruiter, financier and fighter for Al-Qaeda, as well as being a close associate of Osama bin Laden, but never charged him or put him on trial.

The father-of-four, who was twice cleared for release from the camp in 2007 and 2009, denied the allegations and said he was in Afghanistan working for a charity.

Aamer's US lawyer Cori Crider, who is also strategic director at prisoners' rights group Reprieve, said: "We are, of course, delighted that Shaker is on his way back to his home and his family here in the UK.

"It is long, long past time. Shaker now needs to see a doctor, and then get to spend time alone with his family as soon as possible."

Andy Worthington, co-director of the We Stand With Shaker campaign, said Aamer's lawyer had informed him of the release.

"We're delighted to hear that his long and unacceptable ordeal has come to an end," he said.

"We hope he won't be detained by the British authorities on his return and gets the psychological and medical care that he needs to be able to resume his life with his family in London."

'Terrible travesty'  

According to flight-tracking website FlightAware, a Gulfstream jet departed Guantanamo Bay at 11:30 pm local time and was due in London at 12:48 pm local time.

Aamer was born in Saudi Arabia in December 1968, and lived in the US before settling in Britain, where he married a British woman and, in 1996, became a resident.

In 2001, he took his family to Afghanistan, but sent them to Pakistan after the September 11 attacks. He said he was about to join them when he was detained.

Aamer claims to have suffered sleep deprivation, beatings and humiliation at the hands of American troops while being held at the notorious Bagram Prison north of Kabul.

He was transferred to Guantanamo Bay on February 14, 2002 - the day his youngest child was born - where he said the maltreatment continued, leading him to become an advocate for prisoners' rights and an organiser of hunger strikes.

He remained on hunger strike as President Barack Obama's administration announced last month that he was to be freed, leading his family to fear they would not see him again.

A medical examination ordered by his lawyers in December 2013 revealed Aamer was suffering from post-traumatic stress disorder and depression, as well as migraine headaches, asthma and kidney pain.

Rights goup Amnesty International, which took up Aamer's cause, called his detention "intolerable".

"We should remember what a terrible travesty of justice this case has been," said UK director Kate Allen said.

"Having been held in intolerable circumstances for nearly 14 years, Mr Aamer will need to time to readjust to his freedom."

His father-in-law Saeed Siddique earlier this month told AFP that the family had not decided whether to take legal action over his detention.