By Dominic Casciani
Binyam Mohamed spent just under seven years in custody
The UK's human rights watchdog has called for an independent review of claims that British intelligence services colluded in torture.
The Equality and Human Rights Commission says 25 people now claim the UK knew of their mistreatment abroad.
Commission chair Trevor Phillips makes the demand for a review in a letter to Justice Secretary Jack Straw.
It comes after the Court of Appeal told the government to reveal what it knew about the torture of Binyam Mohamed.
In the letter, Mr Phillips says the government has not given good enough answers to allegations that officers from British intelligence agencies had colluded in the alleged torture or mistreatment of terrorism suspects held by the US, or on its behalf by allies, around the world.
Mr Phillips said that an independent review team should get unlimited access to documents and hold public sessions where possible.
He said: "Ministers and government agencies are facing very serious allegations of knowing that UK citizens were being tortured, failing to take action to stop that torture and supplying questions to be used in the interrogation of men who were subjected to a high level of ill-treatment.
"Given the UK's role as a world leader on human rights it would be inexplicable for the government not to urgently put in place an independent review process to assess the truth, or otherwise, of these allegations."
BINYAM MOHAMED TIMELINE
April 2002: Mistreated by US and Pakistani interrogators - arrested in Pakistan over visa irregularities and handed to US authorities as suspected terrorist
May 2002: Washington gives British security officials details of treatment - interviewed by MI5 officers sent from London
July 2002: Flown to Morocco and tortured for 18 months - says his interrogators received questions from London
January 2004: Transferred to Afghanistan and questioned by US agents
September 2004: Taken to Guantanamo Bay - lawyers demand British documents to prove confession extracted during abuse
October 2008: All charges against him dropped
February 2009: Returns to UK and continues fight for release of secret information
February 2010: Court of Appeal ruling forces release of summary of details disclosed by CIA to UK officials about mistreatment
The allegations cited by the Equality and Human Rights Commission include two men jailed for life for serious terrorism offences in the UK, both of whom say they were tortured by Pakistani interrogators before being handed over to British authorities.
Seven of the men referred to by the EHRC are trying to sue both MI5 and MI6 for alleged complicity in their ill-treatment, a case that may take more than a year to come to a full hearing.
The other cases include men whose allegations have been highlighted in recent reports by a UN working group on treatment of terrorism suspects and a separate paper by campaign group Human Rights Watch.
The Court of Appeal's judgement related to Mr Mohamed revealed that MI5 had received detailed reports from Washington of his 2002 mistreatment which included sleep deprivation, shackling and threats of being taken to a third country where he would disappear.
MI5 sent an unnamed officer to interview Mr Mohamed, with the officer's role now being investigated by the Metropolitan Police.
Ministers have insisted repeatedly that MI5 and MI6 do not engage in or collude in torture and specific allegations have not been substantiated. Police are investigating a further allegation of collusion, voluntarily referred by MI6 chiefs.