Delisle, a naval officer stationed in Halifax, pleaded guilty in Nova Scotia provincial court earlier this month to selling military secrets to Russia.
Court documents obtained by the CBC show he had access not only to military secrets, but also files ranging from the Canadian Security Intelligence Service and RCMP to the Privy Council Office.
CSIS said it doesn't know what data on international operations Delisle smuggled out on a thumb drive.
An expert in foreign policy at Dalhousie University said the spy case raises troubling questions about corruption in Russia.
Ken Hanson, a former navy officer, said he questions the motives of the Russian intelligence agency known as GRU.
"The real concern for me is why the GRU is interested in criminal intelligence from Canada? I am afraid that the connection between the GRU and mob activity in Canada is that they are providing, for a price, intelligence to Russian criminal activity in Canada," said Ken Hanson.
How Delisle spied
Delisle's career as a spy started in 2007 when he walked into the Russian Embassy in Ottawa and offered to sell secrets to that country's military intelligence agency.
He was then posted to the security unit HMCS Trinity, an intelligence facility at the naval dockyard in Halifax. While there he worked on a system called the Stone Ghost linking the "Five Eyes" allies: the United States, Britain, Australia, New Zealand and Canada.
Information presented at Delisle's bail hearing detailed how he would browse for material on the secure computer at Trinity, save it in the notepad feature, then transfer it to a floppy disc and thumb drive.
CSIS said the leaks have caused severe and irreparable damage to Canadian interests.
Delisle pleaded guilty, but he has not yet been sentenced. His sentencing hearing is set for two days in early January.