Khaled al-Maqtari's nightmare began when American troops arrived at the al-Ghufran market in Fallujah in January 2004. He was arrested along with other terrorist suspects and taken to Abu Ghraib jail. For the next four years he was held captive, moved from country to country and suffered, he says, appalling torture.

Mr al-Maqtari, from Yemen, was one of the many inmates in the US's secret "ghost detention" who disappeared into an international network of prisons, their whereabouts unknown to family and friends. British soldiers, he claims, were involved in investigating him although they did not play any part in the abuse.

Details of what Mr al-Maqtari, 31, says was done to him emerge after a recent admission from the Foreign Secretary, David Miliband (after previous denials) that the island of Diego Garcia, a British territory, had been used in American rendition flights.

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Amnesty International, in a report into the Yemeni's case, has called for an independent inquiry into the extent of the UK's role in the US's "war on terror" and, especially, rendition flights. An investigation across the Atlantic into the subject was also necessary, says the human rights group, to bring the torturers to justice and provide compensation for the victims.

During his incarceration Mr al-Maqtari was moved from Baghdad to a prison near Kabul in Afghanistan and later in Yemen. In between he was taken to another country, but does not know which. What remained constant, he says was mistreatment which included beatings, cigarettes being stubbed out on his body, being hung upside down, the use of disorienting music and light, starvation, sleep deprivation and being kept naked, hooded and manacled.

Mr al-Maqtari was born in Tabuk, Saudi Arabia, but had lived most of his life in Hodeidah on the Red Sea coast of Yemen. His reason for travelling to Iraq in early 2003 remains unclear as do the reasons for his stays in Mosul, Ramadi and Fallujah, cities which became centres of the Sunni insurgency. Civil rights groups stress, however, that any involvement by Mr al-Maqtari in acts of violence against the Americans does not justify what he says was done to him.

Mr al-Maqtari was working part time in an internet centre in Fallujah when he was arrested in January 2004, seven months after the US-led invasion, a time when insurgents were stepping up their attacks on American forces. According to the US military, its operation "market sweep" led to the confiscation of rifles, machine guns, grenades and mortars. Mr al-Maqtari vehemently denies any connection with this although he was repeatedly questioned about his supposed knowledge of terrorist weapons caches. It was during the searches for hidden weapons that, Mr al-Maqtari claims, British troops became involved. A unit of UK special forces working with the Americans took him from Abu Ghraib to a location in Baghdad, but no arms were found.

Ben Griffin, a former SAS man who was stationed in Baghdad in early 2005, told Amnesty that British special forces would not have taken part in interrogations, but would have been aware of the methods likely to be employed in Abu Ghraib.

Mr al-Maqtari said one of the American interrogators used him as a footstool, trampled on his face and put a cigarette out on his shoulder while shouting, "I'm from New York, the place you Arabs tried to destroy."