Mr Mohamed, a British resident, claims he was tortured in US custody
A senior Tory MP has joined calls for an inquiry into whether UK resident and former Guantanamo detainee Binyam Mohamed was tortured.
David Davis said he was "convinced" that Mr Mohamed was tortured and that the government may have known about - or even colluded with - the torture.
Mr Mohamed, who was detained for seven years, says his torturers received assistance from British intelligence.
Ministers say a decision on an inquiry must await their own investigations.
But they are facing increasing pressure from senior figures - including their own terror watchdog Lord Carlile - to set up a full judicial inquiry.
Mr Davis, a former shadow home secretary, told the BBC's Andrew Marr: "I am convinced... that Binyam Mohamed was actually tortured.
"I am pretty convinced that we knew about it, and I'm reasonably convinced - I think there's a prima facie case - that we colluded in it in some way".
He said if the allegations were true then "a huge number of laws had been broken", and to attempt to cover it up was also a breach of the law.
He said he favoured a "judge-led inquiry" into the torture claims, echoing calls from Lord Carlile who accused ministers of providing only a "limited" account of the UK's role in the abduction and alleged torture of terror suspects.
Lord Carlile told the Sunday Times that a judicial inquiry was needed to look into the claims made Mr Mohamed.
He also favoured an inquiry into the treatment of two al-Qaeda suspects in Afghanistan who the government has now admitted were handed over to American forces by the SAS in 2004.
Mr Mohamed has said British agents supplied "questions and material" to his torturers after he was abducted and flown to Morocco by his American captors.
He was subsequently transferred to Guantanamo Bay, from where he was released to the UK on Monday.
The government has responded to his allegations by asking the Attorney General, Baroness Scotland, to decide whether there should be a criminal investigation.
Asked whether there should be a public inquiry into Mr Mohamed's case, Deputy Prime Minister Harriet Harman told the BBC: "Lord Carlile stands outside the government and gives the government very important advice on this.
"Obviously we will have to listen to what he says but at the moment we have got an investigation by the Attorney General."
Shami Chakrabarti, director of Liberty, said: "Lord Carlile is the government's own reviewer and from a government point of view has always been a safe pair of hands.
"When even he feels a need to call for a judicial inquiry the game must be up and the inquiry will no doubt soon follow."
But there has been mounting criticism at the length of time being taken to decide whether police should investigate the allegations.
This week Keith Vaz, chairman of the Home Affairs Select Committee, said: "To take four months to make a decision of this kind is a very long time. I think we need a decision now."
The Conservatives say there is an "urgent need" for the government to be as transparent as possible about rendition as well as the Binyam Mohamed case.
A spokesman said: "If it fails to do so the case for a wide-ranging inquiry will become steadily stronger."