MI5 could not have stopped soldier's brutal murder

A demonstrator holds a picture of murdered soldier Lee Rigby during a protest outside the Old Bailey courthouse in London February 26, 2014.

LONDON - Britain's security services could not have prevented two men hacking to death a British soldier in broad daylight on a London street last year even though one of the killers had been a high priority in previous inquiries, lawmakers said on Tuesday.

Michael Adebolajo, 29, and Michael Adebowale, 23, both Muslim converts, ran over Lee Rigby near a barracks in Woolwich in May 2013 before setting upon him with knives and a meat cleaver in an attempt to behead him.

They asked bystanders to film them with bloodied hands as terrified locals hurried past, calmly justifying their actions as a response to Britain's foreign policy.

The murder horrified the country but also raised questions for Britain's domestic spy agency MI5 when it emerged they had been aware of the men before the attack.

Parliament's Intelligence and Security Committee (ISC) said in a report however that MI5 could not have stopped the attack.

"We do not consider that, given what the Agencies knew at the time, they were in a position to prevent the murder of Fusilier Lee Rigby," it said.

The committee noted Adebolajo had been investigated by MI5 five times, twice as a high priority, but the spy agency had found no evidence of any attack planning.

The ISC also said Adebowale, who had also been a "low-level" person of interest to MI5, had told an overseas extremist in an online exchange in December 2012 of his intent to murder a soldier, but that this only came to light after the killing.

"Had MI5 had access to this exchange at the time, Adebowale would have become a top priority," ISC chairman Malcolm Rifkind said in a statement. "There is then a significant possibility that MI5 would have been able to prevent the attack."

The ISC said while MI5 and the police needed to concentrate on those who posed the greatest danger, the failure to manage those who might pose a national security risk but were not under active investigation was an issue that had to be addressed.