By Gordon Corera
BBC Security Correspondent
Sir John Scarlett formerly chaired the Joint Intelligence Committee
The head of MI6 has told the BBC there is no torture and "no complicity in torture" by the British secret service.
Sir John Scarlett said his officers were committed to human rights and liberal democracy, but also had to protect the UK against terrorism.
There has been growing concern about the role of the intelligence services in the mistreatment of suspects abroad.
The Joint Human Rights Committee of MPs and peers recently called for an independent inquiry into the matter.
In a highly critical report, the committee said there was now a "disturbing number of credible allegations" of British complicity in torture.
These allegations include the rendition and alleged abuse of British resident Binyam Mohamed from Pakistan to Morocco, prior to being taken to Guantanamo Bay.
However, the committee said it was unable to draw conclusions about the involvement of British officers because ministers and the head of the domestic security service MI5 refused to testify at parliamentary hearings on the claims.
The Metropolitan Police are investigating the role of MI5 in Mr Mohamed's case.
Meanwhile, the Foreign Affairs Select Committee has also said it has grave concerns that British officers were complicit in torture.
Speaking on BBC Radio 4's programme MI6: A Century in Shadows, Sir John Scarlett defended the actions of his organisation, the Secret Intelligence Service or MI6.
"Our officers are as committed to the values and the human rights values of liberal democracy as anybody else," he said.
"They also have the responsibility of protecting the country against terrorism and these issues need to be debated and understood in that context," he added.
He denied that British intelligence services had been compromised by their close relationship with counterparts in the US.
"Our American allies know that we are our own service, that we are here to work for the British interests and the United Kingdom. We're an independent service working to our own laws - nobody else's - and to our own values."
He insisted there has been "no torture and there is no complicity with torture".
Sir John also discussed the controversy over the reliability of intelligence about Iraq's weapons of mass destruction.
At the time, he was the chairman of the Joint Intelligence Committee, which had ownership of the 2002 dossier which contained the controversial claim that Saddam Hussein would be able to deploy weapons of mass destruction "within 45 minutes".
The newly launched Iraq Inquiry is expected to revisit the question of how the intelligence was presented in the dossier.
Citing the earlier Butler inquiry's findings on the matter, Sir John acknowledged that "a number of the reports and reporting lines proved to be unreliable and had to be withdrawn".
"This of course is a regular issue in any kind of intelligence work and if you have lines, reporting chains if you like, then of course there are issues about how you validate them," he said.
Sir John said he had no regrets over the issue, but conceded that the episode had been "a difficult time for the service".
He will step down as the head of MI6 in November.
His comments come a day after Foreign Secretary David Miliband and Home Secretary Alan Johnson both strongly denied allegations of collusion in the abuse of terrorist suspects overseas.
However, they did say it was impossible to remove all risk when using intelligence obtained overseas.
The Liberal Democrat home affairs spokesman, Chris Huhne, said Sir John had denied the involvement of the British secret intelligence service, MI6, and had not spoken about the security service, MI5, against whom the allegations had been directed.
"When you look at the rebuttal you have to see what is being rebutted," he said.
"And when I see that what is being rebutted is not the allegation that was made, call me sceptical and call me cynical if you like, but I actually wonder whether or not there is something going on more than meets the eye."
Mr Huhne added that there was "a very strong case for a public inquiry, a judicial inquiry which will clear the name of this country".
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And the director of the campaign group Liberty, Shami Chakrabarti, told the Today programme that the ongoing claims surrounding torture were damaging the government.
"What the government, and indeed the security establishment are sadly facing at the moment, and have been for some years, is a slow bleed of poisonous revelations, drip by drip, which can't be good for morale and I don't think allow us to move forward from the darkest moments of the war on terror."
Dr Kim Howells, Labour chairman of the intelligence and security committee, told Today it would examine any claims of UK complicity in torture.
"I can tell you that we found no evidence that there's been collusion between the intelligence services, any government department and governments that torture their individuals.
"We can't give a guarantee, and no government on earth can give a guarantee that somebody who's picked up and held in another country hasn't had their... human rights abused in some way."
MI6: A Century in the Shadows
is a three part series for Radio 4.
The final episode,
will be broadcast on Monday 10 August at 0900 BST and 2130 BST or listen again via iPlayer.