Gilles Vaillancourt, the former mayor of Laval, is among a group of 37 facing a slew of charges ranging from fraud to gangsterism after a series of arrests by Quebec’s anti-corruption squad early Thursday.

Vaillancourt, who appeared in a Laval court Thursday afternoon, faces two charges of gangsterism, including one related to directing a criminal organization, which carries a maximum penalty of a life sentence.

The list of 37 people picked up by police Thursday includes other politicians, political aides, lawyers and people with ties to the construction industry, including embattled construction magnate Tony Accurso who is already facing charges of fraud, conspiracy and corruption.

Others arrested include Poly Excavation owner Marc Lefrancois and Vaillancourt’s long-time associate Jean Bertrand.

After appearing in court in handcuffs, Vaillancourt was freed on $150,000 bail without deposit. The 72-year-old was given bail conditions and ordered to surrender his passport. He must re-appear in court July 10.

“I will devote all the time that I have to prove my innocence – and I think I have very strong points,” Vaillancourt told reporters as he left the courthouse.

At a press conference Thursday morning, police said the arrests were the fruit of an investigation that began three years ago.

"The investigation targeted the dismantling of an organized and structured network operating a system of corruption and collusion in the provision of public contracts," said Robert Lafreniere, head of the anti-corruption unit known as UPAC.

"Today's operation is a testimony of the magnitude of the corruption phenomena we are facing."

Police said they obtained approximately 30,000 wiretaps, interviewed 150 witnesses and received more than a thousand tips from the public. They also seized $483,000.

Premier Pauline Marois, who attended the annual meeting of the Quebec’s federation of municipalities, was reserved in her comments on Vaillancourt.

“We have a justice system and I’m confident that these actions will take us closer to restoring integrity in our institutions,” Marois said.

Vaillancourt had served as the mayor of Laval for 23 years before resigning last November amid allegations of corruption. One month before his resignation, police raided Vaillancourt’s home and office and gained access to his bank safety-deposit boxes.

His name was also raised repeatedly in testimony at the Charbonneau Commission, investigating allegations of corruption in the province’s construction industry.

Former construction boss Lino Zambito testified that Vaillancourt took a 2.5-per-cent cut from all construction contracts handed out in Laval.

In 2010, the ex-mayor faced allegations that he gave envelopes stuffed with cash to the Parti Quebecois and awarded contracts to friends and family.

Vaillancourt has always maintained his innocence, blaming a climate of suspicion in Quebec for his departure when he resigned.

"We are going through a very difficult, very painful moment as a society," Vaillancourt told reporters.

"All elected people, at all levels, are accused of all sorts of wrongdoing. We're hearing all sorts of things, we're facing allegations that without being proven can irreversibly change someone's reputation."

He said he was "deeply hurt" and suggested that stepping away from public office was his only option.

"Whatever I say or do... the damage (to my reputation) is done.”

With files from The Canadian Press