Prime Minister Stephen Harper, Defence Minister Peter MacKay, the military and the RCMP turned aside questions on the case of Sub.-Lt. Jeffrey Paul Delisle, who's charged with communicating information to a foreign entity.
Defence experts said, given where the suspect worked, the potential damage to national security was immense.
MacKay said he would not confirm or deny reports the foreign power involved could be Russia, but a defence expert said that country is the most likely suspect, given the few details available.
"I am not going to play Clue," MacKay said during a media availability to trumpet $337 million for a new satellite system intended to make military and government communications more secure.
The case against Delisle was adjourned until next week by a Halifax judge, leaving the mystery to deepen as a neighbour in Bedford, N.S., described him as "someone who kept to himself" since moving from Ontario.
His rented house was turned upside down by RCMP and military police investigators last week.
Defence experts said the Conservative government clearly intends to make an example of the junior intelligence officer, considering the kind of charges that were laid and the fact Justice Minister Rob Nicholson was required to sign off on the case.
The Security of Information Act, the law being used to prosecute Delisle, remains untested in court — never having been used in a case of alleged espionage since its passage in 2001.
"We do not have case law when it comes to breaching official secrets," said Christian Leuprecht, an associate professor of political and defence studies at the Royal Military College and Queen's University, in Kingston, Ont.
"What this case will allow is to build case law on which we can pursue further prosecutions against other individuals. What this signals, in some ways, is we did not just pass an act — we actually think we are going to need to make use of this act."
It fits with the federal government's tough-on-crime agenda and recent measures such as the publishing of a most-wanted list of suspected war criminals, said Leuprecht.
Reid Morden, a former director of the Canadian Security Intelligence Service, noted espionage cases have always been difficult.
"However, this is a new act, and something's got to be first. So my assumption is that they must feel that they've got a fairly good case or they wouldn't have proceeded this way."
Ron Atkey, a lawyer and former chairman of the Security Intelligence Review Committee, said he would be surprised if the case is weak.
"Nothing is a slam dunk in the criminal law, but Justice is pretty careful in bringing cases, and they don't like losing."
The notion the country is besieged with spies has grown since Dick Fadden, director of CSIS, warned that foreign powers were trying to influence Canadian politicians and events. It was reinforced with questions about the possible romantic liaison between junior foreign affairs minister Bob Dechert and a reporter with China's state news agency.
Delisle faces two charges under the Security of Information Act that deal with communicating information over the last five years, and a former commander of the navy said questions need to be asked about the vetting process that allowed him into such a sensitive position.
The officer toiled at Trinity — the handle for the military all-source intelligence "fusion" centre on the East Coast — which would provide tactical assessments primarily to Canadian warships and aircraft — both at home and overseas, said Leuprecht.
Delisle presumably "would have a high-level clearance," said retired vice-admiral Bruce McLean. "Most of the officers in the Canadian Forces would go through a security check, but it would be an enhanced security check if you were working in a more significant area like Trinity."
That means some of the same agencies that pursued Delisle, including CSIS and the RCMP, would have had to sign off on his clearance.
Of even more concern, he said, would be the potential leak of information as to how Canada and its allies go about gathering intelligence.
MacKay flatly refused to discuss what may have been betrayed and said that no one wanted to prejudice the case before the courts.
Wesley Wark, a University of Toronto intelligence expert, said there was no worse place for the Canadian government to have this kind of scandal because fusion centres not only have Canada's secrets, but the sensitive intelligence of other nations.
"If code words and files were compromised, it could cause allies an awful lot of pain. This is the nightmare scenario like the Bradley Manning case," said Wark, referring to the American soldier who allegedly handed over hundreds of thousands of classified documents to online whistleblower WikiLeaks.
MacKay insisted this breach has not damaged Canada's relationship with its allies, saying "our allies have full confidence in Canada."
Leuprecht said Russia would have the most gain from recruiting a spy in an all-source intelligence centre because, as Moscow rebuilds its navy, information on NATO movements and capabilities would represent a gold rush of data.
China is also a possibility, he said, but their spying has been more focused on industrial activity.
Wark, however, said China has been the most aggressive in terms of espionage and shouldn't be ruled out too quickly.
Delisle, 40, did not appear for his bail hearing Tuesday in a Halifax provincial courtroom. He was remanded in custody until his case returns to court on Jan. 25.
Outside court, defence lawyer Cameron MacKeen declined to comment on the case, saying only that there is a presumption of innocence until guilt is proven.
"We just got disclosure today. We need a chance to go over that and make decisions based on what we see," MacKeen said. "People have to realize there's a presumption of innocence in this country and that's something we'll be looking at going forward."
The Crown declined comment.
Court documents say one of the alleged offences happened between July 6, 2007, and Jan. 13, 2012, while the other offence is alleged to have happened between Jan. 10, 2012, and Jan. 13, 2012.
Delisle also faces a breach of trust charge under the Criminal Code that is alleged to have happened between July 6, 2007, and Jan. 13, 2012.
All the offences are alleged to have happened in or near Halifax, Ottawa and Kingston, Ont.
Neighbours said they noticed something was afoot when cars started showing up at Delisle's house late Friday night. They said they'd barely seen him during his time in the quiet bedroom community.
"He was just reserved and didn't mix," said one neighbour who asked not to be identified. "There was quite a few officers, searching his home. They took stuff out. It went on for about six hours."
Morden suspects the gravity of the charges reflects what the police found.
"The search of the house must have revealed something that gave them more confidence to proceed with a more serious charge."
— With files from Alison Auld in Halifax