The ex-wife of the Canadian navy intelligence officer who pleaded guilty to espionage charges in October says that "the Jeff that I married is not the Jeff that did this. It blows my mind that somebody can betray a whole country, ‘cause one marriage failed."

In a documentary that airs tonight on CBC-TV, the fifth estate has an exclusive television interview with Jennifer Delisle, the ex-wife of Jeffrey Delisle, a military intelligence specialist who walked into the Russian Embassy in July 2007 and offered his services as a spy. He continued his espionage work until his arrest in Halifax in January 2012.

When Jennifer and Jeffrey first met 20 years earlier in Lower Sackville, a suburb of Halifax, she was the rebellious teen and he was the straight arrow, known for his integrity. "He was a very black and white kind of guy, and he didn't like people who did black things, so he made me look and strive for higher things," she said in an interview with the fifth estate’s Linden MacIntyre.

"He was the good guy. He was the kind that you looked for. Well, I remember quoting to one of my friends, [I’m] going to date him for a week or two because he's not really my type right now. I'm still into a party mode. But you know, when I want to marry somebody, that might be the guy I look for."

Rocky marriage

Delisle had grown up in a family with a military tradition, and in 1996 he became a reservist specializing in intelligence before joining the Royal Canadian Navy in 2001 and then moving to defence intelligence in Ottawa in 2006.

Sub-Lt. Jeffrey Paul Delisle leaves provincial court in Halifax on Oct. 10, 2012. He will be sentenced on espionage charges later this month. (Andrew Vaughan/Canadian Press)

Jennifer and Jeffrey had married in 1997, a union that produced two girls and then two boys in quick succession, but also increasing discord.

"Our marriage wasn't very good," Jennifer told the fifth estate. "A lot of it stemmed from computer using. He played a lot of games…. for a very long time. So he lived in his own little world."

Jennifer said that she became "very unhappy…. I would nag him. Used to leave little notes on the computer that said, you know, ‘How about dating the other woman tonight,’ meaning me. Meaning that his computer was his first love…. We talked a lot about his computer addiction."

Her husband was apologetic, she said, but did little to change his behaviour. When he discovered his wife was having an affair, however, he was devastated.

Watch Watch the fifth estate documentary The Imperfect Spy on Friday. It airs on CBC-TV at 9 p.m. (9:30 in Newfoundland and Labrador).

During the interrogation following his arrest, Delisle said "I grew up to a strict moral code. Always do the right thing. Always do the right thing. Dependable Jeff. Jeff... Jeff... Jeff... And I get betrayed. My wife told me that she didn't love me for 19 years. She saw me as security. It killed me."

Delisle said he thought of suicide, but couldn’t bear the thought of leaving his children. "So I committed professional suicide. That's what I did, professional suicide," he said.

"The day that I flipped sides? I walked right into the Russian Embassy ... and that was the last day of Jeff Delisle."

Jennifer finds his rationalization difficult to accept. "All marriages have problems, and I think if you were to blame ... what he's done on infidelity, I think that's a very weak excuse. Every Canadian might be going to sell secrets somewhere. I think it's a very poor excuse. And not one I think that many people would stand behind."

Common profile for a spy

David Major, a former head of counter-intelligence for the FBI, told the fifth estate that Delisle’s excuse is a familiar one. "That’s a very common theme we’ve seen from many spies, to make that same statement.… ‘I was at the lowest of my point and therefore I chose this route’ …. People don’t commit espionage because they’re happy, it’s because they are at somewhat of a life crisis. What we call a profound fear of failure as personally defined by them."

In 2007, when Delisle began working for the Russian spy agency, he was an army sergeant based in Ottawa, but during the following years he acquired a university degree, a commission as a naval officer and a beefed-up security classification, all without attracting attention.

In August 2011, Delisle joined HMCS Trinity, a top secret intelligence facility at the naval dockyard in Halifax that tracks vessels entering and exiting Canadian waters via satellites, drones and underwater devices. The centre is a multinational base with access to secret data from NATO countries and the intelligence alliance known as the "Five Eyes," comprising Canada, the U.S., Britain, Australia and New Zealand. Delisle had full access to the top secret information.

Hugh Williamson, a retired navy lieutenant who worked at Trinity until four years ago, specialized in the same threat assessment role assigned to Delisle.

"He's got a job that gives him access to a number of systems that have classified information on Canada, on its allies, on military operations, on police operations, on a number of different things…. And since apparently he was downloading large quantities of documents and passing them out to the Russians there would be an awful lot there which would be of considerable interest."

Easy theft of secrets

Despite the sensitivity of the work, Delisle found it simple to steal secrets. He copied files from a secure computer to a floppy disk, which he would take to an open computer to transfer files to a USB key. After work, he would take the USB key home, log on to a private email account on a server based in Egypt and leave the files there as a draft document. His Russian handlers shared the password for the account and could download the files.

For 4½ years, Delisle was paid $3,000 a month transferred through Money Mart and an Irish intermediary, never meeting face to face with his Russian handlers.

In 2011, however, around the time he moved to Trinity, he was instructed to find a pretext for a trip to Rio de Janeiro. Delisle was still grieving over his failed marriage. He was overweight, diabetic and supporting three children.

The trip would prove disastrous for Delisle. In Rio, he met with his Russian handler, who gave him $50,000 in cash. According to Delisle, he was also told his role would soon change to that of a "pigeon," meaning he would become a contact among other spies active in the Northern Hemisphere.

At some point during his journey that included stopovers in the U.S., he drew the attention of U.S. immigration officials. They alerted the FBI, which tipped off Canadian authorities.

Game over

A period of intense surveillance followed that monitored every moment Delisle touched a computer. Files that had been planted were intercepted after he tried to send them to his Russian handlers.

On Jan. 13, 2012, RCMP officers arrested Delisle near his home in Bedford, N.S., and charged him with breach of trust and giving secret information to a foreign entity. He pleaded guilty to those charges in October and a sentencing hearing is set for later this month.

Even now, Delisle’s ex-wife finds it difficult to conceive of him as a spy.

"I don't think you picture anybody doing that. Betraying your country. Betraying your family. Betraying your loved ones. I mean, OK, so you're really angry at your wife. You want to get back at her. So you bring down all of Canada? And the U.S.? The UN?

"Doesn't seem to make sense to me."

Watch the fifth estate documentary The Imperfect Spy on Friday. It airs on CBC-TV at 9 p.m. (9:30 in Newfoundland and Labrador).