Sub.-Lt. Jeffrey Delisle is escorted from provincial court in Halifax. (Andrew Vaughan/Canadian Press)

Navy spy Sub-Lt. Jeffrey Delisle, who has pleaded guilty to selling vast amounts of top secret material to the Russians, had access to top-level files while performing his job preparing threat assessments for navy ships.

In his confession interview with the RCMP, Delisle described his job by saying, "I prepare all the threat assessments for the ships when they deploy overseas, to any port."

A retired naval intelligence officer, who had the same profession as Delisle, said this meant Delisle had access to files and secret information supplied by CSIS, the CIA, FBI and British intelligence sources.

"There is a need to know requirement," said Hugh Williams. "Based on what he is looking at and based in that area, he would would be looking at information from a wide variety of sources."

Delisle's access to high-level information is what makes his betrayal such a concern for Canada and its allies. His job as the threat assessment officer for the Canadian navy in the Atlantic opened secret doors that would be closed to other officers. Delisle gathered and sold information to the Russians for $3,000 a month.

Delisle was posted to the security unit HMCS Trinity, an intelligence facility at the naval dockyard in Halifax. It tracks vessels entering and exiting Canadian waters via satellites, drones and underwater devices.

Delisle, 41, pleaded guilty in a Halifax court Oct. 9 to breach of trust and two counts of passing information to a foreign entity between July 2007 and Jan. 13, 2011, in Ottawa and Kingston, Ont., and Halifax and Bedford, N.S., where he lived.

Delisle will be sentenced for spying in January. He is currently in jail but on full navy pay and maintains his rank in the service.