The disgraced ex-mayor once known as the King of Laval has cast a dark shadow over the city's municipal election, with fresh allegations supported by a secret recording that he offered cash to one candidate and delivered a thinly veiled threat against another.

In the midst of the new allegations against Gilles Vaillancourt, the mayor who reigned over Laval for 23 years before his downfall, a campaign staffer who helped blow the whistle on Mr. Vaillancourt was beaten on the side of a road by two men. He was not seriously injured in the Monday night attack.

Earlier Monday, candidate and former Vaillancourt ally on council, Claire Le Bel, went public to Radio-Canada with her recording of a meeting with Mr. Vaillancourt in August where the former mayor suggested he could secretly deliver shady cash donors to help fund her campaign. She and her children have been under police guard since she went public.

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Fellow mayoral candidate Marc Demers, a former Laval police investigator and long-time enemy of Mr. Vaillancourt, said he went to police Tuesday to complain that Mr. Vaillancourt was also recorded telling Ms. Le Bel that Mr. Demers would have his legs broken.

The violence and revelations spoke to Laval's status as the epicentre of Quebec's runaway corruption scandal. It also illustrated the long, enduring reach of Mr. Vaillancourt, who ruled Laval nearly unopposed until his resignation a year ago. He was arrested in May on charges of fraud, bribery and gangsterism, and is out on bail awaiting trial.

Mr. Vaillancourt even told Ms. Le Bel "a new system is already in place" to replace the kickback, bribery and bid-fixing regime he is accused of running when he was mayor.

"You know, even if there's a new law, even if everyone says, 'My hands are now clean, I'm now clean,' the reality is there's already another system," he said in an excerpt aired by Radio-Canada.

A few hours after some of the recording was broadcast Monday, Ms. Le Bel's campaign manager, Rény Gagnon, was forced to pull over on a Montreal freeway because of a flat tire. He was approached by two men, beaten and told to keep his mouth shut. Mr. Gagnon was not seriously hurt, according to Ms. Le Bel.

Mr. Vaillancourt could not be reached for comment, and his lawyers did not respond to requests for information on Tuesday. Ms. Le Bel said she has no evidence the attack on Mr. Gagnon was linked to the release of the recording of Mr. Vaillancourt the same day.

Ms. Le Bel said she has been living in fear since Mr. Vaillancourt first approached her Aug. 13. She went to police with the recording one week later, she said.

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Mr. Demers criticized Ms. Lebel for failing to go public with the recording for two months. "I don't know how you would feel if somebody threatened to make attempts to break your legs and somebody withheld that information for months," he said in an interview. "I think it's a lack of judgment. Just deciding to meet with Mr. Vaillancourt shows a lack of judgment."

Ms. Le Bel said she held off because she didn't want to hinder any investigations.

"But once the investigation is going nowhere, people have a right to know," she said in an interview. "I was afraid. But I finally jumped in with both feet [Tuesday] morning, and I can say that I already feel better. When the fear, the secret were hanging out there, it was terrible. But when you have a big secret and say it out loud, it's certainly a relief."

Ms. Le Bel said voters have the right to know Mr. Vaillancourt is trying to influence the Nov. 3 election.

"There are so many questions," Mr. Demers said. "Why is he obsessed with taking control of city hall? Why is he taking all these chances? There are still a lot of things still being hidden at city hall. Some people are clearly very worried."

The Charbonneau inquiry heard several weeks of testimony over the past two years that described how Mr. Vaillancourt was at the centre of a ring that rigged public bidding in the city, arranged for bribes and kickbacks, and produced vast sums for illegal campaign financing. When Mr. Vaillancourt was arrested, investigators said he and his acolytes were collecting 2.5 per cent on every public contract awarded by the city of Laval.

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Mr. Vaillancourt was among three-dozen people charged with gangsterism, fraud and bribery, but he was the only person specifically named as the leader of the ring. He and the others are scheduled for a preliminary hearing next summer.