LONDON (Reuters) - British agents did not circumvent the law by using data gathered by a clandestine U.S. spy programme, the head of an influential British parliamentary committee said on Wednesday, but added the framework governing such access did need to be re-examined.
Former U.S. security contractor Edward Snowden released details of the PRISM programme last month to the media, lifting the lid on what he called a vast surveillance system that vacuumed up emails and phone data.
Leaked documents showed the data was sometimes handed over to Britain's security services.
Parliament's Intelligence and Security Committee (ISC) launched an inquiry after the Guardian newspaper reported allegations that Britain's GCHQ surveillance agency circumvented British laws protecting the privacy of communications by accessing data from the U.S. programme.
The committee's chairman Malcolm Rifkind, a former foreign secretary and a senior figure in the Conservative party that leads Britain's coalition government, said that had the allegations been true, it would have been extremely damaging to GCHQ and would have had serious implications for public trust in the intelligence services.
However, his committee concluded the claims were unfounded.
"Did they break the law or attempt to break the law? Our answer is unreservedly and unanimously no they did not," Rifkind told reporters.
Rifkind said their findings showed Snowden should not have leaked the information in the first place.
"The very fact that today we are saying ... the allegations that arose out of Mr Snowden's behaviour turn out to be totally unfounded and unjustified, illustrates that individuals who may think they are serving public interest in some occasions ... may turn out to be absolutely wrong," he said.
But he also said it was time for his committee to look into the laws on eavesdropping and communications surveillance to see if they were adequate. There are three acts governing Britain's spy agencies' access to private communication.
Privacy campaigners said the fact GCHQ had not broken the law did not mean Britain's spy agencies should be given a clean bill of health.
"If the law is not fit for purpose, the question of not breaking it is largely irrelevant," said Nick Pickles, director of civil liberties campaign group Big Brother Watch. "When the Intelligence and Security Committee is raising concerns that the current legal framework is adequate, alarm bells should be ringing loud and clear that all is not well."
Snowden, 30, is stuck in a transit area at Moscow's Sheremetyevo airport where he hopes Russia will grant him temporary asylum. U.S. President Barack Obama's administration wants Russia to send him back to face trial.
In its report, the Guardian said PRISM had generated 197 intelligence reports for GCHQ, allowing it to bypass legal restrictions on access to personal material such as emails held by internet companies based outside Britain.
The ISC said it had examined the classified reports and found they were put together legally. The agency had possessed a warrant for interception signed by a government minister each time it asked for information from the United States.
"I was surprised by the thoroughness and detail that are required when authorisation is needed from the secretary of state," Rifkind said.
However, he said his committee had only had time to focus on the most serious allegations relating to illegality.
He said further claims that emerged from Snowden's leaks that GCHQ spies had tapped fibre-optic cables carrying international phone and internet traffic might be studied at a later date.
"We are still a long way from getting to the bottom of what has been happening," said Pickles.
Additional reporting by Andrew Osborn and Peter Griffiths; Editing by Andrew Heavens and Tom Pfeiffer