The CBC French-language network's investigative program spoke to a businessman who said he had taken part in systemic corruption.
The man, who spoke on condition of anonymity, described a system in which construction companies and engineering firms are alleged to have paid millions of dollars in cash bribes to one-time Laval mayor Claude Ulysse Lefebvre and to one of his fundraisers, in order to obtain contracts with Quebec's third largest city.
"We had no choice but to come up with the cash," the source told Enquête.
He said the money went into secret accounts connected to Lefebvre, who was mayor from 1981 until 1989.
"There have always been secret accounts in Laval," the source suggested to Enquête.
Asked if the system was created to steal money from taxpayers, the businessman agreed.
"Yes, for sure. You could say that. It was really to steal from citizens," he said.
Enquête's investigation showed that the system of bribery and corruption would have allowed Lefebvre and his fundraiser to amass more than $1 million illegally each year.
"The system began under the [previous] regime of Lucien Paiement," said André Cédilot, a crime writer and former investigative journalist with the French-language newspaper La Presse. "It was refined under the regime of Claude Ulysse Lefebvre, and it flourished under the administration of Mayor [Gilles] Vaillancourt."
Source's claim mirrors Zambito's testimony
The former head of the now-defunct construction firm Infrabec made similar claims in his explosive testimony before Quebec's inquiry into corruption in the construction industry in October.
Lino Zambito told the Charbonneau commission that Vaillancourt routinely collected a 2.5 per cent kickback on public works contracts.
Zambito described how he was told by an intermediary for Vaillancourt that if he wanted "extras" for cost overruns to be authorized, he would have to hand over $25,000 in cash, destined for the mayor.
Vaillancourt, who resigned from office on Nov. 9 in the wake of mounting corruption allegations, refused to speak with Enquête, but he has repeatedly denied all allegations against him.
"We’re facing allegations that, even without proof, are altering the reputations of those in whom you have placed your trust. 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 said on the day he stepped down as mayor.
Paiement, who was Laval's mayor between 1973 and 1981, and Lefebvre both denied to Enquête that they had secret accounts.
"That is innuendo about me that I, of course, am revolted by," Lefebvre told Enquête.
Quebec's anti-corruption squad, UPAC, has carried out a series of raids in Laval in recent weeks, targeting Vaillancourt's home and former offices, as well as construction and engineering-consulting firms.
UPAC's investigation into allegations of corruption and collusion under Vaillancourt continues.
No charges have been laid against Vaillancourt or any other elected official in Laval.