MONTREAL—Laval mayor Gilles Vaillancourt said he would not step down on Friday, barely 24 hours after officers from the Surete du Quebec’s anti-corruption squad raided his home and office at city hall.

"What I am facing came as a total shock to me. It was totally unexpected," said Vaillancourt, who adamantly denied knowing why he was the latest target of the SQ.

The 23 year mayor of Laval is the highest-profile target yet for UPAC, the special anti-corruption unit formed in 2009.

"I will collaborate with police. I cannot offer any idea as to why I am under investigation," said Vaillancourt. “It is not a pleasant situation.”

After making a brief statement in French and English, Vaillancourt left the room where he was holding a news conference, refusing to answer any questions. The mayor told the assembled audience that his conference was a sign of his commitment to transparency.

Seventy officers from the SQ, working as part of “Operation Hammer,” searched four locations on Thursday, only wrapping up their investigation at 2:00 a.m. The raids came as part of the province’s multi-year effort to tackle economic crime and municipal corruption.

Vaillancourt's spokesperson said the mayor would fully co-operate with police, or with the Charbonneau Commission if asked.

"We don't want to interfere with what the UPAC is doing. They have a job to do. The mayor knows about that. He respects the mandate. So they will do their job," said spokeswoman Joanne Bournivale, referring to the acronym of the SQ’s anti-corruption squad.

Earlier this year a former fundraiser for the Parti Quebecois said that Vaillancourt gave the provincial party $10,000 in cash during the 1994 election.

Claude Vallee reportedly gave police that statement in a written affidavit in the summer of 2011.

In July, Vaillancourt denied any such event had taken place. He has also denied offering money to former PQ cabinet minister Serge Menard and to Liberal Vincent Auclair.

While he has faced some scandal during his time at the helm of Quebec’s third largest municipality, Vaillancourt has never been charged with any crime.

"This morning we are seeing a flurry of allegations, rumours and demands," he said. He added, pausing for emphasis after each word: "I. Will. Not. Resign."

—with files from The Canadian Press.