Canada’s spy chief says he can’t guarantee there won’t be another case of a Canadian spilling secrets to a foreign power, despite heightened security in the wake of the Jeffrey Delisle scandal.

However, the case spurred Canada and its allies to review and upgrade the “security arrangements” that govern the most top-secret dealings between them.

Canadian Security Intelligence Service director Dick Fadden told the Senate national security and defence committee Monday that the Delisle case was neither “catastrophic” nor an incident that could be dismissed as a one-off.

Last week, Sub-Lt. Delisle was sentenced to 20 years in jail for breach of trust and communicating information to a foreign entity that could harm Canada’s interests. Delisle was paid more than $100,000 for classified material he passed to Russian agents over nearly a five-year period.

Fadden told the committee that the Delisle case “is one case that we caught. I suspect there will be others over time, both here and within our allies.”

According to Fadden, the Delisle case did not make Canada an international pariah among its allies.

"I think what saves us -- if that's the right word -- in these instances with our allies is that every single one of them has been in the same situation before," Fadden said. "Having said this, I think there's a consensus amongst ourselves and our close allies that this has been to some degree the straw that broke the camel's back.

"And it's caused ourselves and a number of our close allies to review the security arrangements that have been in place within our countries and between our countries."

Delisle was arrested in 2012 after a lengthy probe and accused of passing secrets to the Russians between 2007 and 2011. He was the first person charged under the Security of Information Act, which was passed following the Sept. 11, 2001 terrorist attacks.

Delisle was based at an intelligence centre in Halifax, where he could access data shared between Canada, Britain, the United States, Australia and New Zealand. He transferred information that mentioned Russia to floppy disks and memory sticks, and then passed it along via an email address he shared with a Russian agent.

Fadden said despite the fact that Delisle was having personal troubles, he didn’t raise the suspicions of top brass.

"He was divorced, he was having financial problems, and his family was breaking up. That probably defines a large part of the Canadian population, unfortunately," Fadden said.

"So they alone, I don't think, would have been enough for a red flag to have flashed. I think in retrospect an orange flag would have been worthwhile. But he didn't do anything obvious that would lead either ourselves or the Defence Department to believe he was a traitor. He sort of chugged along, he was a relatively quiet guy, didn't make a big fuss."

Fadden also told the senators Monday that CSIS officials remain unclear about the exact details of all the information Delisle passed on.

"The technique that Delisle used allowed him to effectively eliminate the material transferred after it had been received,” Fadden said.

He said defence and security officials are working together to shore up electronic data security procedures.

With files from The Canadian Press