'Full torture probe may be needed'
A full judicial inquiry may still be required into allegations of British complicity in torture if police and parliamentary probes fail to answer key questions, Nick Clegg said.
The Deputy Prime Minister said he was absolutely sure that at the present time torture "cannot, will not and is not being used under any circumstances by British agencies or indeed on our behest".
But with the publication of a damning report into the interrogation of detainees by America's CIA sparking renewed calls for a more detailed examination of Britain's role in the rendition of terror suspects, he accepted one might be needed.
An inquiry by judge Sir Peter Gibson was halted pending police inquiries but raised 27 areas requiring further investigation, ranging from interrogation techniques to so-called "rendition flights", the training of agents and ministerial oversight of the agencies.
They are now being examined by the parliamentary Intelligence and Security Committee (ISC) - a move which campaigners argue is insufficiently independent.
Mr Clegg said during his weekly LBC radio phone-in: "Once the police investigations are done, once the report from the Intelligence and Security Committee is done, we should keep an open mind if we need to about moving to a full judicial inquiry if there are any outstanding questions.
"I'm like anybody else: I want the truth out there."
He went on: "However shocking the Senate committee report is, it's worth remembering that I doubt very much any state run by Isil or al Qaida would ever have the maturity to lift the lid on its own mistakes in the way a mature democracy like America has done."
Mr Clegg said the Senate committee report included the "devastating assertion that it (torture) didn't actually keep us safe" and may in fact have led to resources being wasted on false trails.
Prime Minister David Cameron has declared himself "satisfied that our system is dealing with all these issues".
The Senate committee said the interrogation of detainees in the wake of the 9/11 attacks were "far worse" than the CIA had portrayed to the US government.
Waterboarding methods had deteriorated to "a series of near drownings" and agency staff subjected detainees to "rectal rehydration" and other painful procedures which were never approved, the report said.
The CIA justified its use of so-called enhanced interrogation techniques with "inaccurate claims of their effectiveness" including examples of thwarted UK plots such as a plan by 9/11 mastermind Khalid Sheikh Mohammed to hijack planes and attack Heathrow Airport and Canary Wharf.
The revelations also add weight to calls for the release of t he last British prisoner being held in Guantanamo Bay, an MP has said.
Shaker Aamer, who is originally from Saudi Arabia but moved to Battersea in south London and has a wife and four children there, has been incarcerated at the US military prison since 2002.
His local MP, Conservative health minister Jane Ellison, told the Daily Mail: " Shaker Aamer's continued detention in Guantanamo Bay is unacceptable.
"The UK Government has confirmed repeatedly that they want him released to the UK and the latest revelations serve to underline that Shaker Aamer should be immediately reunited with his family in Battersea."
Aamer, one of just over 100 prisoners left at the notorious detention centre, has been held there without charge for 12 years, accused of being a close associate of Osama bin Laden, something he denies.
The 47-year-old's lawyer, Clive Stafford Smith, claims the reason for his continued detention is a fear that he will reveal details of brutality he is alleged to have suffered, as well as what he has witnessed happening to other prisoners.
"Shaker knows too much. National embarrassment isn't a reason to keep a man who has been cleared for release locked away in prison. Shaker must be returned to his family in London at once," said Mr Smith.
Aamer was detained in Kabul, Afghanistan, in 2001 after, his representatives claim, he went to the country to carry out voluntary work for an Islamic charity.
It is alleged that he was tortured at the Bagram air force base while being questioned by US forces and in February 2010 it emerged that the Metropolitan Police were investigating allegations of MI5 complicity in his torture.
Asked if the Prime Minister also had an open mind on the possible need for a full inquiry, a Downing Street spokeswoman said: "Our focus is to let the ISC get on with their work. They are due to report at the end of next year. Let's see what they say and what's needed."
She said the UK continued to press the case at the highest levels for Aamer's release "as a matter of urgency".
"We will keep pressing it. We want to make progress together. It is our objective to get him back to the UK. That decision is in the hands of the US government.
"We are doing all we can to work with the US to encourage them to reach a decision."