An unidentified source quoted in a police affidavit claims that former Mayor Gerald Tremblay was aware of a scheme to get 10 percent back from companies that won city contracts, a sum to be equally divided between the party and the Montreal Mafia.

The document was compiled by the UPAC police anti-corruption squad investigation in order to obtain a search warrant four years ago but was not accompanied by supporting evidence to back up the claim.

The UPAC unit used the document in a request for a search warrant for telephone records belonging to Tremblay’s onetime second-in-command Frank Zampino.

A judge made the recordings public following a legal initiative led by a consortium of media outlets including the Gazette and La Presse newspapers.

The unidentified source said that Mafia-related firms were given an advantage in obtaining contracts under the city's collusion system and that Tremblay was aware of the scheme which saw half of the 10 percent go back to the party and the rest going to the mob.

Tremblay, now 71, served as mayor from 2002 to 2012 and has always maintained that took part in, and knew nothing of corruption within his administration.

Mayor Denis Coderre told CTV Montreal that the allegations should be judged not in the court of public opinion but rather in a court of law, if evidence warrants.

"We’ll let justice follow its course. Mr. Tremblay is a private citizen now. He has the right to defend himself and you can ask him as a citizen what he thinks about it," said Coderre.