A British security service officer visited Morocco three times during the period that the former terror suspect Binyam Mohamed claims he was secretly tortured by the CIA, according to new evidence that raises further questions over British involvement in US acts of "extraordinary rendition".
The UK Government has repeatedly insisted it was not aware Mr Mohamed, a former Guantanamo detainee, was in Morocco and Afghanistan in 2002 and 2003, a year before being taken to the prison camp. But documents shown to the High Court yesterday suggested an MI5 officer, known as "Witness B", had made three visits to Morocco during the period Mr Mohamed alleges he was held and tortured there.
Yesterday, Lord Justice Thomas said he had taken the "very unusual step" of reissuing a revised judgment on a ruling on secret evidence in Mr Mohamed's case originally made last year. It said that by September 2002 it was clear to the security agency that Mr Mohamed was being held in a covert location, but that they were "unable to determine the significance (if any) of the visits of the MI5 official".
The revision adds further pressure on the Government to disclose exactly what MI5 and other government officials knew about the US involvements with the British resident.
Lawyers for David Miliband, the Foreign Secretary, told the court earlier this week that if the summary of CIA documents was published, the US would limit intelligence-sharing with the UK, a move that "would put lives at risk". But this new evidence is set to challenge that assertion again.
Describing it as a "strange coincidence", human rights charity Reprieve said the revised judgment revealed that British secret services made a far greater contribution to Mr Mohamed's interrogation than they originally admitted.
Reprieve's director Clive Stafford Smith said: "The British agents clearly committed perjury when telling the court that they did not know of Binyam's illegal detention at a CIA 'black site' and that all efforts to question Binyam ended in February 2003. How high up in the British Government did this sordid truth travel?"
Chairman of the House of Commons Select Committee, Keith Vaz, called for an official explanation into the officer's role, while shadow Foreign Secretary William Hague said that until the Government disclosed the role of the officer in Morocco, the "damaging impression that Britain may have been complicit in torture will not be dispelled".
Mr Mohamed, 30, a former UK resident who was arrested in Pakistan in 2002, alleges that during three months of detention he was tortured by Pakistani agents.
He says he was then taken to Morocco on an "extraordinary rendition" mission by the CIA with the explicit knowledge of the British security service. During further torture in Morocco, he says, he became aware that his torturers were being fed questions and material from British intelligence agents. The Government denies the claims.
Last night the Home Office would not be drawn on individual cases but said that "the Government unreservedly condemns the use of torture as a matter of fundamental principle."