No collusion in torture - MI6 chief

Speaking to the BBC, Sir John Scarlett said: "Our officers are as committed to the values and the human rights values of liberal democracy as anybody else."

His comments came as the Government faced mounting calls for an independent inquiry into possible British complicity in overseas torture, despite a public assurance by Cabinet ministers David Miliband and Alan Johnson on the issue.

Foreign Secretary Mr Miliband and Home Secretary Mr Johnson spoke out as a second influential parliamentary committee expressed concerns that the UK could be in breach of legal obligations by regularly using information from suspect sources.

Speaking on BBC Radio 4's programme MI6: A Century in Shadows, Sir John defended the actions of the Secret Intelligence Service, better known as MI6.

He said: "(Our officers) have the responsibility of protecting the country against terrorism and these issues need to be debated and understood in that context."

He also stressed that British intelligence services had not been compromised by close relationships with similar services 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," Sir John said. "We're an independent service working to our own laws - nobody else's - and to our own values."

Mr Miliband and Mr Johnson used a Sunday newspaper article to insist every effort was made to ensure intelligence gained from terror suspects held abroad was not obtained through torture.

But they said there could be no 100% guarantee that such methods were not used, claiming tough judgments had to be made between the possibility and the need to protect the UK from attack.

Amnesty International dismissed their statements as "excuses" as campaigners, politicians and Muslim groups all joined the demands for an official inquiry.