Canadian police were tipped off by the FBI to a possible security breach by a Canadian navy intelligence officer who later pleaded guilty to espionage, documents made public Thursday say.
Redacted versions of three search warrants were released Thursday after the prosecution consented to their release.
The warrants were used to obtain evidence against Sub-Lt. Jeffrey Paul Delisle, who pleaded guilty last month to passing classified information to Russia.
Delisle worked at a naval intelligence center in Halifax, Nova Scotia and had access to secret data from NATO countries.
One document said police opened an investigation into Delisle's activities after it received a letter in late 2011 from FBI assistant director Frank Figliuzzi alerting them of a possible security breach involving a Canadian military officer. That letter was sent Dec. 2, 2011, about six weeks before Delisle was arrested
The portions of the documents that were released do not elaborate on how or when the FBI became aware of the security breach. But they do indicate that the Royal Canadian Mounted Police heavily relied on information from Anthony Buckmeier, a Russian counter-espionage specialist who began working for the FBI in 1987.
"Given his vast experience in Russian counter-espionage, I believe the information supported by the opinion of Anthony M. Buckmeier is credible," says a warrant filed by the RCMP.
The documents say the RCMP set up phone taps from Montreal as they pursued their investigation into Delisle's activities. Delisle was arrested Jan. 13.
The documents also say Delisle received a total of 23 money transfers from July 6, 2007, to Aug. 1, 2011 from Moscow and Ireland.
During his bail hearing in March, the provincial court in Halifax heard that Delisle walked into the Russian embassy in Ottawa and offered to sell them information. Over the course of nearly five years, Delisle accepted money transfers from Russia in exchange for his services, the court was told.
There was a publication ban on evidence and arguments presented at the proceedings in the spring, but his guilty plea means there will not be a jury trial now. Sentencing is scheduled for Jan. 10.
Delisle would search for Russian references on his work computer, transfer it to a USB key and take it to his home nearby before pasting it into an email program that he shared with his Russian handler, the prosecution has said.
But at some point, the RCMP hacked into the email account Delisle shared with his Russian handler, the court heard. Delisle continued sending sensitive information through the account, unaware that police were receiving it.
Delisle, who joined the navy as a reservist in 1996, became a member of the regular forces in 2001 and was promoted to an officer rank in 2008. He had access to systems with information shared by the Five Eyes community that includes Canada, the United States, Britain, Australia and New Zealand.