Ex-Laval mayor Gilles Vaillancourt says he's not guilty of several charges related to corruption during his reign as mayor.

The embattled former mayor of Laval, Que., appeared in court this afternoon to face 12 charges, including conspiracy, fraud, influence peddling, breach of trust and gangsterism.

Anti-corruption crusader and Coalition Avenir Québec MNA Jacques Duchesneau says this is the first time in Quebec's history that a politician has faced charges of gangsterism.

One of the gangsterism charges Vaillancourt faces carries a maximum sentence of life in prison.

"I will devote all the time I have to prove my innocence, and I think I have strong points," Vaillancourt told the media outside the Laval courthouse in a brief statement.

He then asked journalists to respect his privacy, saying he is now a "private person."

Vaillancourt's lawyer, Nadine Touma, says her client has not yet entered a plea but that he will plead not guilty.

Quebec's anti-corruption unit, UPAC, arrested 37 people this morning, including Vaillancourt.

The former director of engineering in Laval, Claude Deguise, and the former city manager, Claude Asselin, are also accused of gangsterism.

The unit also arrested former construction entrepreneur Tony Accurso and former Dessau Engineering executive Rosaire Sauriol in a provincewide sweep.

Quebec's anti-corruption unit Created by the provinical government in 2011 in response to allegations of questionable practices related to the awarding of publc works contracts.

Known as UPAC.

Executed 450 search warrants, received more than 800 tips and made 49 arrests in 2012.

Raided the home and offices of Vaillancourt last October.

"We [executed] 70 search warrants," said UPAC commisssioner Robert Lafrenière. "We captured approximately 30,000 wiretapped conversations. We have recovered $438,000. One hundred and twenty police officers are involved in today's operation."

Vaillancourt was picked up at his Laval apartment early this morning and taken to provincial police headquarters for questioning.

It's the latest arrest for Accurso, who faces allegations of tax evasion as well as fraud, conspiracy, influence-peddling, breach of trust and defrauding the government in connection with an investigation into how the Montreal-area municipality of Mascouche awarded more than $40 million in contracts.

Vaillancourt resigned in November amid mounting pressure from a UPAC investigation and testimony before the province's corruption commission. A few weeks prior the former mayor's safety deposit boxes were searched by UPAC investigators.

Rosaire Sauriol resigned as vice-president of the engineering firm Dessau, founded by his father, days after testifying before the province's corruption commission. (Charbonneau commission) That raid coincided with allegations against the mayor that surfaced at the Charbonneau inquiry into corruption in Quebec's construction industry.

A key witness, the former head of the now-bankrupt construction firm Infrabec, Lino Zambito, testified Vaillancourt collected a 2.5 per cent kickback on all public works contracts.

At the time of his resignation, Vaillancourt continued to deny all allegations of corruption.

"We’re facing allegations that, even without proof, are altering the reputations of those in whom you have placed your trust," he said in November. "I am one of these people, and I have been deeply hurt. Regardless of what I do or say, it is clear that the damage has been done."

Vaillancourt was a political fixture in Laval, on Montreal's North Shore, for nearly four decades. For the 10 years prior to his resignation, his PRO-des-Lavallois party was unopposed at city hall.

Managers arrested

The latest arrests come several days after the city's manager, Gaétan Turbide, and assistant city manager, Jean Roberge, were suspended from their duties, with pay, for an indeterminate time.

The two men are scheduled to appear as witnesses next week at the province's corruption commission.

Turbide and Roberge worked closely with Vaillancourt.

Laval city council unanimously backed interim mayor Alexandre Duplessis in his motion to suspend the two employees.