The background: A man called David and an irresistible offer

It was a freezing December morning in 2002 at the Forest Prison in Brussels when the young Moroccan received a knock on his cell door. A man called David introduced himself as being attached to the British embassy in Belgium and said he wanted to talk to him.

He claimed he knew who he was and why he was imprisoned. He also said he wanted to help. A few weeks later David made a second visit. This time he told the Moroccan that his prospects didn't look good and then delivered this stark message: "I've made some enquiries and discovered that no one really wants you. You are a stateless person."

The journey that took the Moroccan to the high-security jail began in a village just outside Rabat in the 1980s. He had grown up in poverty, from a broken home and brought up by his maternal grandmother. When he was just 16 years old he decided to seek a better life in Europe. He reached Spain's Costa del Sol where for nearly two years he went from city to city, from mosque to mosque, living off the handouts of Islamic charity.

Eventually he made his way to Britain where he found a temporary home among the Muslim communities of London. He had entered Britain illegally, had no money and could not find work.

Still only 18 he was vulnerable to extremist propaganda and in 2001 he was persuaded to leave London for Chechnya where he was told that his brother Muslims were fighting a repressive Russian occupation.

But as he approached the Georgian-Chechnya border he had an attack of nerves. Having no intention of entering a war zone, he decided to return to London where he immediately fell under the suspicion of the security services. Hoping to escape both the attention of MI5 and the influences of Islamic extremism, he fled to continental Europe where he sought refuge with his relatives. But while in the Netherlands in December 2001 he was arrested for travelling under a false name and handed over to the Belgian authorities. Belgium's counter-terrorism services had rounded up 16 Muslim suspects, two of whom said they knew the Moroccan. Their testimony sealed his fate and with no more evidence than of "associating with terror suspects" and being in possession of false papers, he was sentenced to four years' imprisonment, two of which were suspended. He was taken to the overcrowded Forest Prison in Brussels where he was held in solitary confinement, able to leave his cell for only one hour a day.

Contemplating the prospect of either years of imprisonment in Belgium or deportation to Morocco where he faced possible detention and torture, the Moroccan knew that his future was bleak.

In late 2003 David visited him in prison again. This time he revealed his true identity, told him that he worked for MI5 and said he wanted to make him an offer. If the young Moroccan agreed to work for the UK's Security Service he would arrange for his immediate release and flight to London.

In April 2004 David and other members of the Security Service arrived at the prison and led the Moroccan out of his cell and out of the prison gates. He was driven to Brussels airport where he was told to board a 20-seat jet chartered by the British Government. He was told to remain in his seat throughout the flight and that he couldn't use the aircraft's lavatory. At Gatwick Airport he was given a passport and led through customs before being driven to a large country house, 40 minutes from London.

In this peaceful rural setting he was questioned for nearly two weeks by senior MI5 officers. They asked him about what he knew of jihad and showed him photographs of people they believed were linked to terrorism. Finally he was warned that if he double-crossed MI5 his life would be in danger.

He was given false papers and set up in a flat in London. As long as he supplied his handlers with information hundreds of pounds were paid into his bank account each month.

When in June 2004 the criminal court in Brussels resumed the hearing, it had not been told that the Moroccan was now in London, and his whereabouts was a mystery.

A year later, Christophe Marchand, his lawyer in Brussels, was contacted by his client, who told him he was phoning from London where he was working for MI5.

Britain and rendition: The story so far

2001 More than 1,000 secret CIA flights pass over EU territory in 2001-06 linked to US rendition programme.

2002 A British resident, Binyam Mohamed, is captured in Pakistan and flown to Morocco where, he later claims, he undergoes torture at a CIA so-called "black site" with the involvement of British and US intelligence agencies. After his ordeal in Morocco, he spends four months in the CIA's "Dark Prison" in Kabul, and is then flown to Guantanamo.

2004 Bisher al-Rawi and Jamil El-Banna, two British residents, "rendered to detention" by the US in December, first to Afghanistan and then to Guantanamo.

2005 Claims emerge that British airports had been used by the CIA for extraordinary rendition flights.

2006 The British Government insists it knows of no requests after 9/11 from the US to use British airspace for extraordinary rendition. It later says it has no evidence CIA flights that are known to have passed through Britain are for rendition.

2007 Flight logs provide first evidence of CIA flights to Diego Garcia, the British overseas territory in the Indian Ocean. Bisher al-Rawi, who was a key source of intelligence for MI5, gives a full insider's account of being seized by the CIA and bundled on to an illegal "torture flight". He is taken to Guantanamo Bay in 2003 before being returned to Britain after four years' detention without charge.

2008 Britain's denials that its territories have been used for extraordinary rendition are undermined after the UN claims Diego Garcia has been used as a detention centre to hold US suspects. Britain admits that US rendition flights carrying terror suspects twice landed on British soil. David Miliband, the Foreign Secretary at the time, is forced to apologise to Parliament that, contrary to previous US assurances, two flights did land at Diego Garcia.

2009 In February the then Defence Secretary John Hutton confirms that two individuals captured by UK forces in Iraq were subsequently moved to Afghanistan by the US.

2010 The Government rejects parliamentary proposals for new laws to stamp out the UK's involvement in the kidnap and unlawful transfer of terror suspects to third-party states. In February, the Court of Appeal finds some MI5 officials have not been "frank" about their involvement in the "mistreatment" of Binyam Mohamed and that there is reason to distrust government assurances to the contrary. A judicial inquiry is announced by the Foreign Secretary William Hague to investigate officials alleged to have been involved in rendition since 9/11.