LONDON - Six weeks after a British militant who is suspected of being an Islamic State executioner slipped out of the country, police sent a letter asking him to surrender his passport, a security bungle that has drawn criticism from opposition lawmakers.

Though the masked militant who was shown directing the killing of five men in an IS propaganda video has not been officially identified, media including the BBC and the Daily Telegraph have named him as Siddhartha Dhar, a Londoner who once sold inflatable bouncy castle toys.

Dhar, 32, left Britain for Syria in September 2014 while on police bail after his arrest on suspicion of belonging to a banned group and encouraging terrorism.

"The system has failed because it allowed him to abscond to Syria," Andy Burnham, the home affairs spokesman for the opposition Labour Party, said in parliament on Tuesday.

"Even if the correct procedures were followed, I have evidence that they were far too weak," he said.

Britain’s independent reviewer of terrorism laws said the main failing in the Dhar case was not asking him to hand over his travel papers immediately.

Burnham cited a police letter to Dhar dated Nov. 7, 2014 setting out bail conditions, including surrendering his passport, that was sent six weeks after the militant had left Britain. In the letter, Dhar, who was said to have fled with his pregnant wife and four children, was urged to contact police.

Dhar turned up in Syria two weeks after the letter was sent brandishing a gun and a baby and taunting Britain for its "shoddy" security that allowed him to "breeze" into Syria.(Reuters)