A tit-for-tat battle among promoters has devolved into a Montreal police crackdown on all amateur tournaments related to kick-boxing, MMA, jiu-jitsu and muay thai, say people connected with the city's fighting community.

Organizers of a Brazilian jiu-jitsu tournament scheduled for last Sunday in Montreal were the latest victims of police enforcing a 2013 Criminal Code amendment outlawing "prizefighting."

Tournament spokesman Danny Vu told The Canadian Press on Tuesday that police informed organizers they are banning all amateur competitions of combat sports not included in the program of the International Olympic Committee or the International Paralympic Committee.

Judo and tae kwon do are allowed, while kick-boxing and other amateur combat sports such as mixed martial arts and jiu-jitsu are now illegal.

Organizers were left scrambling to find another host city for last weekend's Brazilian jiu-jitsu tournament, which had been held in Montreal for the last eight years.

City police said they notified the heads of the Canada National Pro Jiu-Jitsu Championship in response to a complaint about the event.

According to the Criminal Code, all amateur combat sports not sanctioned by the Olympics or specifically designated by the provinces are considered "prizefighting" and illegal.

The police aren't releasing the identity of the complainant, but Montreal-based fighting promoter Jamie McGowan said he believes whoever did it "definitely was malicious and had a vendetta."

McGowan, who said he's held tournaments for kick-boxing, MMA, jiu-jitsu and muay thai for the last 10 years, claims people have been using complaints to police as a way to seek revenge on rivals.

He said he's had three criminal complaints filed against him since January 2015.

"Since (these sports) were criminalized in 2013, for four years they were tolerated and flying under the radar," he said.

But then police started to receive complaints, McGowan explained, which triggered an investigation that has led to the blanket ban in the city.

McGowan said he had a falling-out with a business partner who complained to police in 2015 in order to "disrupt" one of his events.

Then, one year later, the Quebec Amateur Kick-Boxing Corporation also went to the police trying to shut him down, he said.

Pierre Breton, head of the kick-boxing organization, confirmed the story.

"Yes, we did," he said point-blank. "One year ago. We are jealous about retaining the responsibility of supervising amateur kick-boxing galas in Quebec."

Breton said his complaint was followed by a series of other objections made to police -- including some against him.

And what started out as a tactic to get rid of a competitor has seemingly backfired because Breton's group can no longer sponsor kick-boxing events.

"They found out the hard way they aren't legal either," McGowan said.

But Breton refutes this claim.

He sent a letter to The Canadian Press signed by an employee of Quebec's Sports and Recreation Department, confirming his organization is recognized and subsidized by the provincial government.

The letter states Quebec is trying to come up with a policy to clarify what non-Olympics amateur combat sports will be permitted in the province.

Breton said he is confident his organization will soon be sanctioned by the province.

McGowan is less confident about his future hosting competitions.

"If his organization gets legalized then we are all still illegal," he said.

Martin Nguyen, one of the organizers of the cancelled Brazilian jiu-jitsu event, said he has no evidence a rival complained in order to disrupt the tournament.

Additionally, he wanted to make clear that Brazilian jiu-jitsu is not like mixed martial arts or other kinds of amateur combat sports.

"People who do (Brazilian) jiu-jitsu are lawyers, policemen, professionals -- it's not the same thing as amateur mixed martial arts," he said.

"We're being bunched with the rest of them and if it is the case that the war between their promoters (has led us to) become collateral (damage), well that's a shame."

Other people who have suffered the effects of the promoter war and the police crackdown include the Soltes family, who planned to travel to Montreal last weekend from Niagara Falls, Ont., to enter their nine-year-old son in the tournament.

Sabrina Soltes said her son, Alexander, was being bullied in school before he started practising the sport.

"I can't tell you how much my son's grades have improved -- like crazy," she said, about the effects of the sport on her child.

"His self-confidence has improved," she said. "I would never as a mother put my son in danger. I can't praise this sport enough for what it has done for my son."