COTE ST-LUC -- A hotly contested mayoral race playing out in the Montreal suburb of Cote St-Luc has become so negative that police are now involved.

Anonymous letters some are describing as intimidating have been mailed to residents.

“[It’s] very, very uncomfortable,” said incumbent mayor Mitchell Brownstein. “There's no place for that in our society.”

Seeking a third mandate, Brownstein said the tone of this election feels very nasty compared to past races.

He said at least five different anonymous, unsigned flyers have been mailed to some residents within the last year. The most recent was also shared in a local Facebook group.

The latest letter attacks Brownstein's character and leadership on everything from COVID-19 to transparency and claims he cares more about his image than his constituents.

It's unclear how many of the flyers were distributed, but Brownstein says some constituents and his staff find it intimidating.

He gave the letter to Montreal police and also to Elections Quebec to determine if it violates election rules.

“It's very difficult for someone in political life to deal with social media and then have to deal with anonymous flyers attacking one's reputation,” he said.

Brownstein's opponent, Cote St-Luc city councillor David Tordjman, agrees it's been a divisive campaign.

“There are issues of transparency, how we spend taxpayer money, and our investment in our infrastructure,” he said.

Tordjman said that neither he nor anyone on his team is responsible for the flyers.

“Everything that comes from my team has our name on it,” he said. “Everything that I say is about our policies.”

Tordjman said he believes the flyers may have come from an angry voter.

“It's unfortunate that letters like these have to go out, that people feel they don't have a voice and they can't say these things," he said, "but we denounce it."

Tordjman said so far no one from Montreal police or Elections Quebec has contacted him.

Montreal police confirmed, though, that they're looking into the matter. Elections Quebec won't confirm or deny whether they are also investigating.

“I only know it's from someone who doesn't want me as mayor, and I have to leave it to the police to determine where it's coming from,” said Brownstein.

Municipal elections are on Nov. 7.