Former foreign affairs minister Maxime Bernier responds during question period in the House of Commons earlier this month. (Tom Hanson/Canadian Press)

Prime Minister Stephen Harper on Tuesday cast doubt on allegations someone planted electronic listening devices in the home of Maxime Bernier's former girlfriend, Julie Couillard.

"I have absolutely no information that would suggest that is true," Harper said in Paris, where he started a three-day European trip.

Couillard, the woman at the centre of the controversy that led to Maxime Bernier's resignation as foreign affairs minister on Monday, said in a television interview that a private security firm found evidence that an electronic listening device had been removed from her bed.

"They came to my house and they swept my house to see if they could find any bugs. They could not find any bugs, but they definitely came to the professional conclusion that there was proof of a bug that [was] there that [had been] taken out," Couillard said.

Speaking in question period Tuesday, government house leader Peter Van Loan was asked whether the RCMP or the Canadian Security Intelligence Service (CSIS) bugged Couillard's home.

"I have no information … but I can tell you that this government is not in the business of investigating the private lives of private citizens," said Van Loan.

Experts disagree on claim

Former Canadian intelligence agent and RCMP officer Michel Juneau-Katsuya, now a private consultant, told CBC News that if the allegations were true, the bug could have been planted by government security operatives.

Juneau-Katsuya said a government agency could have gone into damage control mode.

"It definitely could have been the government because here we need to know exactly what was going on," he said, adding the agency could have been his own former employer, the Canadian Security Intelligence Service.

Other security experts said they were dubious any listening devices had been planted.

"I think it's somebody's 15 minutes of fame, listening to her interviews on the thing," said Reid Morden, a former director of the Canadian Security Intelligence Service.

Former RCMP officer Chris Mathers, now a security consultant, cast doubt on the notion someone would try to listen in on Bernier and Couillard's pillow talk.

"I find her story remarkable. I'd like to see the evidence of a device being planted, or talk to the technicians, before I'd even begin to believe her," he said.

Embarrassing questions for Harper

CBC chief political correspondent Keith Boag says Harper is bound to face many more potentially embarrassing questions in the days ahead.

"If [the bug allegation] is true, it leads to questions to the prime minister about how concerned he was with this several weeks ago when he said this was all just of interest to busybodies," Boag said. "Is he more interested now than he used to be, and if he is, then what is the course of action that he intends to follow?"

Couillard also told the Quebec television network TVA that Bernier knew of her ties to Montreal biker gangs and organized crime figures.

She also said Bernier, 45, did not press her on her past relationships, but seemed somewhat surprised when she told him last summer.

"Maxime knew about it," Couillard said during the interview, which was taped Sunday.

Bernier resigned from his cabinet position ahead of the broadcast of the interview, after informing Harper he had inadvertently left a classified document at an unsecured location.

Couillard, 38, said Bernier left the document behind when he visited her house sometime in April. She said she consulted a lawyer, who told her it was Canadian government property.

"The document was given back," she said.

She did not disclose what was in the document, but said it was addressed to Bernier and not to her, and it made her "very uncomfortable."

'Not a biker chick': Couillard

Couillard insisted she was doing the interview to re-establish her dignity and credibility after intense media scrutiny following revelations she had links to Quebec bikers. "I've never been accused of any criminal wrongdoing," she said. "I am definitely not a biker's chick."

Couillard lived with Gilles Giguère, a well-known Montreal crime figure, for three years beginning in 1993. He was gunned down in 1996 when he decided to become a police informer after being arrested with a cache of submachine guns and marijuana.

Couillard insisted that Giguère was not a biker and only knew Bob Savard, who knew Hells Angels kingpin Maurice (Mom) Boucher.

In 1997, she began dating and later married Stéphane Sirois, who admitted to being an enforcer for the Rockers, a Hells Angels puppet club. He later turned informant and testified against a dozen of his former colleagues in a 2002 trial.

With files from the Canadian Press