10/07/2013 11:23 EDT | Updated 12/07/2013 05:12 EST

Quebec cop tasked with watching biker gangs arrested on suspicion he helped them

MONTREAL - Quebec's latest corruption scandal has reached into the heart of law enforcement, with a high-ranking organized crime investigator accused of conspiring with the criminals he'd been watching.

Benoit Roberge was the Montreal police force's leading expert on biker gangs, having investigated them and testified at their trials before he retired last year. His spouse, meanwhile, still works as a prosecutor specializing in organized crime.

Now Roberge is under arrest.

He is accused of selling sensitive information about ongoing police investigations to biker gangs and he now faces four charges, including two counts of gangsterism.

On Saturday, he was arrested by fellow police officers. When he was stopped he was allegedly in the company of an individual linked to the Hells Angels crime gang.

The prosecution has been forced to take special precautions in a case it calls especially worrisome.

"This case is difficult because it brings a lot of questions about the justice system," said Crown spokesman Rene Verret.

"It's very disturbing."

Roberge appeared in court on Monday on four charges: one count of obstructing justice, one count of breach of trust and the two counts related to gangsterism.

He will return Thursday for a bail hearing.

The former detective-sergeant retired from the Montreal police force in August. The longtime organized-crime investigator had most recently been assigned to a specialized unit comprising different police forces that focused on biker activities.

Since then, he had been heading Revenue Quebec's intelligence-gathering unit as of March. The provincial tax agency said in a statement that Roberge has been suspended pending the outcome of the criminal investigation.

Provincial police Insp. Michel Forget said Monday that police thought there might have been information being leaked for at least a few months. Such suspected "irregularities" triggered an internal investigation that led to Roberge.

"The investigation will demonstrate what period of time exactly Mr. Roberge leaked information on organized-crime investigations," Forget said.

"But do we suspect (it happened) for all of his career? We are not there yet."

According to the charges filed by the Crown, the charges against the accused stem from acts committed in his final years as a police officer — between 2010 and October 2013.

The infractions are alleged to have taken place in towns east of Montreal.

"The investigation demonstrated that he transmitted pertinent information to organized-crime figures in relation to ongoing investigations in return for some amounts of money," Forget said.

Forget said a provincial police tactical squad was used to arrest Roberge and his unnamed companion on Montreal's South Shore.

The arrest follows a similar high-profile case.

A Montreal police detective killed himself in January 2012 while under investigation over whether he peddled a list of police informants to the Mafia. Ian Davidson took his own life after being outed as a mole in different newspaper reports.

Forget sought to address the issue of public trust.

He said accusations of criminal infiltration are taken seriously and leaks are investigated quickly. He said the actions of one person should not reflect on other officers who are dedicated to the fight on organized crime.

"Organized crime has gotten to such a level that its members will do everything to infiltrate police forces," Forget said.

"Any form of infiltration will be repressed."

The Quebec prosecutor's office has announced an increase in security measures to protect its files.

One of its attorneys, Nancy Potvin of the organized-crime division, is married to Roberge. She is currently on holiday.

Verret, the Crown's spokesman, said it's not clear if she will be reassigned to other duties.

In any case, as a result of her ties to the accused, exceptional measures have been taken to find a prosecutor from outside Montreal, Verret said.

The prosecutor in court Monday was from Quebec City, he said.

There is also a possibility that a prosecutor might eventually be called in from outside the province, although no such decision has been made.