article_snippet: But the man apparently double-crossed the man British handlers and returned to London with plans to launch an 'insider attack' in the capital.
article_snippet: Parts of the alleged plot for more than a year were reported in a story in The Mail on Sunday last year, in which we revealed that the jihadist, who has a British passport, had plans to attack Central London and that David Cameron had been briefed about the details.
article_snippet: A long undercover operation was run by MI5 to try to identify linked individuals who might be travelling back from Syria to launch similar attacks but the investigation has now concluded, meaning we can now report the fact that he was a potential 'double agent'.
article_snippet: Investigators believe the man met a terrorist mastermind with designs on attacking the West who encouraged the man to plan an attack.
article_snippet: The alleged 'double agent' was apparently planning to use the firearms to stage a murderous attack on the public in an echo of the Kenyan shopping mall massacre last year, sources said.
article_snippet: the man remained in contact with the man jihadi controller, a terrorist mastermind who is thought to have established links to Britain.
article_snippet: The alleged 'double agent' also joined up with another extremist and another extremist approached two other men for help in obtaining the equipment, but two other men did not agree to help two other men.
article_snippet: Eleven months after The alleged 'double agent' was allegedly planning his attack, police and MI5 rounded up another cell linked to IS also allegedly planning a gun attack in Central London.
highlights_snippet: An undercover operation was launched to try and track any similar plots .
  