Reportedly on several occasions, Siddhartha Dhar, also known as Abu Rumaysah, was approached by British intelligence officers and offered the chance to work as a double agent. He was told that he would most likely be imprisoned or die, according to the Sunday Times.

Dhar's response to the job offer in September remains unclear but shortly after he was arrested, Dhar skipped police bail and fled to Syria with his family, Daily Mail Reports.

The revelations come amid widespread speculation that Siddhartha Dhar is the masked executor, dubbed Jihadi Sid, who featured in a graphic latest ISIS video last week.

The video footage showed five Syrian men being executed for alleged espionage. The leading ISIS fighter in the video appears to have a prominent British accent and gives a threatening message, claiming that ISIS will invade the UK.

“Jihadi Sid” (In the Right)

UK Police and the Home Office have come under growing pressure to answer questions about security lapses that allowed Dhar to slip through the net.

Dhar left Britain for Syria in September 2014 despite being on police bail and having been arrested on six occasions. His fled also raised questions about Britain's borders, because they departing on a coach from London with his family the day after he was released on bail.