Surjan Singh Gill was a suspect in the bombing of Air India Flight 182, and has been alleged to have been a possible Canadian Security Intelligence Service (CSIS) mole.
Gill referred to himself by the self-proclaimed title of "Consular General of Khalistan", and was a member of Babbar Khalsa until three days before the bombing . It has been suggested that CSIS wanted to pull "their man" out of the group as soon as they realised that a serious plot was underway and about to take place.
Although a central figure in the investigation, Gill was never charged and disappeared after flying to the United Kingdom.
References
Surjan Singh Gill Wikipedia(Text) CC BY-SA