Maxime Bernier arrives to be sworn in at Rideau Hall last August. He is accompanied by Julie Couillard, whose revelations about classified documents left at her home last month led to Bernier's downfall. (Paul Chiasson/Canadian Press)

Prime Minister Stephen Harper said he doesn't believe national security was compromised after classified documents were left at the home of the former girlfriend of Maxime Bernier, as the government dismissed opposition calls for an inquiry into the matter.

Harper made the comments in Paris at the beginning of a three-day visit to Europe, as his government deals with the fallout from the former foreign affairs minister's surprise resignation on Monday.

"We have no information that would indicate that documents have circulated," Harper told reporters in French. "The documents were returned to the government of Canada. But it is our intention to review the incident to ensure that is the case. But thus far, we have no information that would suggest that any secrets have been revealed."

Speaking during question period Tuesday, government House leader Peter Van Loan said the documents included a mix of publicly available information and classified material related to preparations for the NATO summit in Bucharest in April. Canada had hoped to secure more troop commitments in Afghanistan from its allies at the summit.

Bernier had come under much criticism in recent weeks as connections between his ex-girlfriend Julie Couillard and Quebec biker gang members and organized crime figures emerged in the press.

Liberal Leader Stéphane Dion said Harper showed an "appalling lack of judgment" by failing to respond to weeks of opposition questions about Bernier's links to Couillard.

"The prime minister must have [a] public inquiry," said Dion.

Van Loan, who responded to all opposition questions on Bernier's resignation, said the Foreign Affairs Department will examine the situation and ask for assistance if needed.

The documents were returned to the federal government late on Sunday and Harper became aware of the security breach only on Monday, said Van Loan.

"The prime minister acted as soon as he was aware," he said.

Documents left for 5 weeks

Couillard told a French-language television interviewer in Quebec late Monday that the documents in question had been left in her home in April. She said she didn't read them, but said they had made her "very uncomfortable."

On Monday, during a hastily arranged news conference to announce Bernier's resignation, Harper said that Bernier's departure from cabinet had nothing to do with his private life.

"I don't think it matters who a minister is dating," Harper told reporters in Ottawa on Monday. "I don't think it matters anything about the private life of some private citizen; what matters here is that rules respecting government classified documents were broken."

He repeated it on Tuesday, saying Bernier's resignation had nothing to do with his relationship with Couillard.

"This was the unfortunate error, the unfortunate actions of the minister that are at issue here."

CBC's chief political correspondent Keith Boag said the resignation will have a considerable impact on the reputation and confidence of the government.

"It makes it almost certain that we'll have a bigger cabinet shuffle this summer as the prime minister has to figure out what dominoes to move around now that Mr. Bernier's not there," Boag said.

International Trade Minister David Emerson and Heritage Minister Josée Verner will pick up Bernier's cabinet responsibilities while the prime minister searches for a new foreign affairs minister.

Opposition calls for probe

Bernier, 45, has also been in a weakened position in recent weeks since a gaffe in April during a visit to Afghanistan, where he publicly suggested the removal of the governor of Kandahar.

Earlier this month, the federal government was forced to rent a Russian cargo jet to ship helicopters to Burma to deliver aid after Bernier publicly promised the Canadian military's new C-17 transports, none of which were immediately available, would handle the job.

Montreal newspaper Le Devoir reported Monday that Couillard, who was once married to a bike gang member, owns a firm that bid on an airport security contract.

Opposition foreign affairs critic Bob Rae told CBC News that the affair had damaged Canada's reputation among its allies, and there needed to be some form of inquiry into the security implications of the lost documents.

"We've been calling for this for weeks," Rae said, "and we were told we were snoops. It took a television interview to come up with the simple information that Madame Couillard had access to information that she shouldn't have had. There has to be an investigation."

Rae referred to the government's handling of the affair as "amateur hour on the Rideau."

NDP Leader Jack Layton said it was about time that Bernier was replaced after committing a "series of incompetencies."

Layton told the Globe and Mail that the RCMP needed to take a broad look at the allegations raised during Couillard's TV interview Monday night.

Speaking to reporters after the announcement, Bloc Québécois Leader Gilles Duceppe rejected Harper's contention that Bernier's resignation had nothing to do with Couillard's highly anticipated interview.

Duceppe said many questions remain unanswered, including how "people with very strange pasts" can bid on government contracts for airport security.

Former girlfriend had been married to bike gang member

Le Devoir reported Monday that Couillard's business specializes in "systems of high security technology" that include security system installations and passenger security.

The information was provided to Le Devoir by a former employee at Couillard's firm.

Couillard, 38, received documents regarding airport security, according to the report.

Published reports have referred to court documents that say Couillard was once married to a member of the Rockers biker gang, and was a potential target of alleged Hells Angels kingpin Maurice (Mom) Boucher while she dated another biker.

Couillard has said she cut off those ties in 1999, and her romantic involvement with bikers is part of a distant past.

She started dating Bernier before he was sworn in as foreign affairs minister in 2007. They recently split up.

Couillard said her name and reputation have been tarnished because of published reports documenting her past ties, but she is not ashamed of anything.

With files from the Canadian Press