MI6 does not pass on intelligence to foreign agencies if it believes that it could result in torture, even if it could prevent terrorist activity taking place, the head of the service has said.
In the first public speech by a serving Chief of the Secret Intelligence Service (SIS), Known officially as MI6, Sir John Sawers strongly defended its methods while appealing for understanding for the "real, constant, operational dilemmas" it faced.
Speaking to the Society of Editors in London in a live television address, he said it is essential that agents and overseas intelligence services could be confident that their secrets would not be compromised through working with MI6.
He expressed concern that the possible release of intelligence material received from foreign agencies in recent court cases could lead to intelligence-sharing with key allies drying up.
Sir John stressed that SIS had "nothing whatsoever" to do with torture, which was both "illegal and abhorrent", and that he was confident that its officers acted with the "utmost integrity". At the same, he said that they had to operate in the "world as it is", which, on occasion, meant working with agencies from countries which were not "friendly democracies", which could throw up difficult issues.
"Suppose we receive credible intelligence that might save lives, here or abroad. We have a professional and moral duty to act on it. We will normally want to share it with those who can save those lives," Sir John said.
"We also have a duty do what we can to ensure that a partner service will respect human rights. That is not always straightforward. Yet if we hold back, and don't pass that intelligence, out of concern that a suspect terrorist may be badly treated, innocent lives may be lost that we could have saved."
Sometimes, he said, there was no clear way forward and the most "finely-balanced" cases had to be decided by ministers. However SIS would always strive to prevent terrorist attacks in a way that was consistent with human rights.
"If we know or believe action by us will lead to torture taking place, we're required by UK and international law to avoid that action. And we do, even though that allows the terrorist activity to go ahead," he said.
Sir John said that he welcomed the announcement of the Gibson Inquiry into alleged complicity by officers from SIS and the Security Service, MI5, in the torture or abuse of detainees held abroad.