Mr Mohamed has felt "betrayed" by Britain over his detention
In total, Binyam Mohamed spent just under seven years in custody - four of those were at the US's Guantanamo Bay camp in Cuba.
US authorities considered him a would-be bomber who fought alongside the Taliban in Afghanistan, following his arrest in Pakistan in 2002.
But Mr Mohamed has insisted the only evidence against him was obtained using torture. Last year the US dropped all charges against him.
Mr Mohamed was said to be very ill as a result of a hunger strike in the weeks before his release, while US authorities were reviewing his case.
Conversion to Islam
Binyam Mohamed al Habashi was born in Ethiopia on 24 July 1978.
In 1994 he arrived in the UK and sought asylum on the basis of his family's opposition to the Ethiopian government.
His application was rejected, but in 2000 he was given exceptional leave to remain in the UK for four years.
Living in North Kensington, west London, Mr Mohamed worked as a cleaner and studied electrical and electronics engineering.
In 2001 - the year he converted to Islam - Mr Mohamed travelled to Pakistan, and then Afghanistan. What he was doing there was the crux of his legal battle.
US President Barack Obama has ordered the closure of Guantanamo
According to Mr Mohamed, he wanted to kick a drug habit and get away from familiar haunts in London.
He says that he also wanted to see whether Taliban-run Afghanistan was a good Islamic country - a path followed by other young Muslim men who were fascinated by events in that war-torn region.
US authorities, however, said that while in Afghanistan Mr Mohamed fought on the front line against anti-Taliban Northern Alliance forces.
They claim he was cherry-picked by al-Qaeda because of his UK residency, and received firearms and explosives training alongside British shoe bomber Richard Reid.
Prosecutors claimed he planned to travel to the US, rent several flats in an apartment block and then blow it up with a timing device.
Mr Mohamed was arrested by Pakistani immigration officials at Karachi airport in April 2002 when intending to return to the UK.
He alleges that he was tortured in Pakistan, Morocco and Afghanistan between 2002 and 2004, including being beaten and scalded and having his penis slashed with a scalpel.
He claims a British agent who introduced himself as "John" visited him in Pakistan and that the torture stopped soon afterwards.
But he was later taken to Morocco, where he says he was tortured for a period of 18 months.
In a statement following his release and return to the UK, he said that during all his time in detention "the very worst moment came when I realised in Morocco that the people who were torturing me were receiving questions and materials from British intelligence".
He claims he was then transferred to an alleged CIA-run site in Kabul, Afghanistan, before being sent to Guantanamo in September 2004.
In Afghanistan he alleges he was held in a black hole at the "Prison of Darkness" where he was deprived of sleep, blasted with sound, starved and then beaten and hung up.
Release of evidence
In August 2007, Britain asked the US to return Mr Mohamed and others to the UK. Other detainees were returned, Mr Mohamed was not.
Mr Mohamed spoke at fundraising event in August 2009
Then, when it became clear the US was going to re-charge Mr Mohamed, his lawyers sought the release of evidence relating to the case.
When the UK government declined, his lawyers started High Court proceedings on 6 May 2008 culminating in a February 2009 ruling that referred to the claims of torture.
Judges refused to order the disclosure of a summary of US reports on his detention, citing a threat to US intelligence-sharing with Britain - although the foreign secretary said there had been no such threat and the UK "never condoned torture".
The US charged Mr Mohamed, in May last year, with conspiring with members of al-Qaeda to murder and commit terrorism.
Mr Mohamed was among the Guantanamo detainees who went on hunger strike to protest against the conditions and their lack of access to a judicial review.
In a May 2008 letter to Downing Street, he told how he felt "betrayed" by Britain and said he was contemplating suicide.
He wrote: "I have been held without trial by the US for six years, one month and 12 days.
"That is 2,234 days (very long days and often longer nights). Of this, about 550 days were in a torture chamber in Morocco and about 150 in the 'Dark Prison' in Kabul.
"Still there is no end in sight, no prospect of a fair trial."
In October 2008, the US announced that charges against Mr Mohammed and four other men were being dropped.
In December, Mr Mohamed was told unofficially that he would be freed when the new US administration came into office.
But he reportedly went on another hunger strike between 5 January and 11 February, only stopping when a member of his legal team persuaded him that his release was imminent.
British officials, including a doctor, visited Mr Mohamed in Cuba on 15 February to assess whether he was fit to be brought back to the UK.
Confirmation of Mr Mohamed's release was made in a Foreign Office statement on 20 February.
Since he arrived in Britain on the 23 February, Mr Mohamed has endeavoured to avoid the limelight and live a quiet life.
He is among a group of former detainees who were all held at secret detention centres around the world who are collectively suing the British government.
They claim the government did not take sufficient steps to ensure they were released or protect them from ill-treatment, including torture.
The legal action is almost certainly going to run for a number of years.