The parents and former spouse of a Canadian naval officer accused of leaking sensitive information to Russia were "stunned" by the espionage allegations, CTV's Ottawa Bureau Chief Robert Fife reports.

Fife tracked down Sub.-Lt. Jeffrey Paul Delisle's ex-spouse and spoke to her current partner, who said the accused officer had no apparent ties to Russian operatives. The mother of Delisle's two children was shocked by his arrest, Fife reported Friday night.

Delisle, 40, faces two charges under Canada's Security of Information Act and is alleged to have passed on sensitive information to a foreign entity. Sources have told CTV News that information was leaked to Russia.

Fife exclusively reported Thursday that four Russian embassy staffers were expelled from Canada as a result. Officials in Moscow denied that, saying the staffers went home because their contracts in Canada had finished up.

On Friday, Moscow officials reiterated that explanation in a public statement posted on Twitter.

"Canadian media reports of Russian diplomats being expelled from (Canada) are surprising, as they left in 2011 on completing their secondment," said a tweet from the Russian foreign ministry.

The officials in question include two unnamed embassy workers and Lt.-Col. Dmitry Fedorchatenko and Konstantin Kolpakov.

Other media reports suggest that the workers left Canada weeks before the scandal broke.

Ottawa is remaining tightlipped about its investigation of Delisle because it doesn't want Russians to pick up any clues about how the alleged crime was discovered, Fife reported.

Foreign Affairs Minister John Baird hasn't publicly commented on the issue, and has only stated that the matter is before the courts.

"On a national security file like this, I am not inclined to comment," said a statement from Baird's office this week.

But Baird's silence could be an attempt to defuse what could become an international imbroglio, Fife reported Thursday.

Indeed, with Prime Minister Stephen Harper set to visit Russian on an official visit later this year, officials are concerned that Ottawa and Moscow could get locked into a tit-for-tat expulsion of diplomats.

Despite Canada's silence on the issue, the scandal likely won't go away any time soon.

"Sources say Delisle undoubtedly had access to current operational intelligence," Fife reported.

That intelligence could include sensitive data on navy ship movements in Middle East and the Arctic, plus information on underwater dead zones, which Russian navy officials could use for covert submarine missions.

"But the real worry is the nightmare scenario," said Fife. "Did he have access to classified information, classified as beyond secret?"

That extra sensitive information may have included communication signals from spies, both Canadian and American, working abroad.

"If he had access to that information, sources say this would be a goldmine for the Russians," Fife said.

According to allegations, the Russians recruited Delisle in 2007 when he was working as an intelligence officer for the navy in Ottawa.

None of the allegations have been proven in court.