OTTAWA - The Harper government says Foreign Affairs Minister Maxime Bernier's recent romantic liaison is no threat to national security, despite a news report that said his ex-girlfriend's links to the criminal underworld were more recent than previously thought.

But the Conservatives refused to say whether authorities investigated the affair or took any other measures that allowed them to conclude there was no threat.

Bernier's former relationship became political fodder once again Friday after Montreal's La Presse newspaper reported that Julie Couillard lived with a man with ties to the Hells Angels three years ago.

Couillard's penchant for bikers and bad-boys was thought to have been limited to one husband and one live-in boyfriend before 1999.

But La Presse said she lived until 2005 with Robert Pepin, who the newspaper said owed money to a Hells Angels loanshark when he committed suicide last year and once pleaded guilty to trafficking stolen goods.

Sometime between the end of her relationship with Pepin and her appearance with Bernier at a cabinet swearing-in ceremony last summer, she began dating the minister.

Security experts and opposition parties say a relationship between a cabinet minister and a someone with criminal ties poses a handful of potential security risks.

People close to Bernier have described how his ex-girlfriend took an active enough interest in his professional life that it annoyed some of his departmental staff.

But when asked whether it had done anything to check for a security breach, the government dismissed the risk.

"This is not an issue of national security,'' said Conservative House Leader Peter Van Loan. "We have made it clear that this government would not put national security at risk.''

What he and other government officials have repeatedly refused to answer is whether anything has been done in recent days or months to examine several questions.

Those questions include whether Bernier shared sensitive information with Couillard and whether he was aware of her past while they dated.

The Liberals defended their line of questioning after Van Loan cast it as base gossip-mongering.

"Frankly, I'm stunned that the minister and government continue to take the position that this has nothing to do with the public interest,'' said Liberal MP Bob Rae.

A spokeswoman for the Privy Council Office said the minister would only have been screened when he was first named to cabinet -- as industry minister in 2006, which is before he was ever seen in public with Couillard.

Another government official says that while checks are only done once, ministers are always told to advise the Prime Minister's Office or PCO if there are any material changes in their lives, including marital difficulties.

In the case of Bernier, the official said the minister would have been obliged to disclose Couillard's past -- if he knew about it.

When a reporter approached Couillard's modest two-storey brick home near Montreal to ask her about the latest report Friday, she waved him away.

Earlier this month, Couillard dismissed the controversy as politically motivated.

The government was equally dismissive of another opposition question about Bernier.

Rae asked why he reportedly spent $22,573 for a flight to Laos, when other staff members travelling with him claimed between $2,676 to $18,500 in airline expenses.

Rae suggested the figure seemed exorbitant.

To which Van Loan replied:

"The (Liberal) party has been saying . . . that it is concerned that it wants to see Canada stand tall on the world stage and now it is being critical of the concept of the foreign affairs minister actually representing Canada at international forums,'' he said.

"We have every intention of continuing to stand up for Canada on the world stage.''