Two members of the Montreal police department's anti-gang squad are facing criminal charges after an internal investigation alleged they lied to get search warrants and one of them traded for sexual favours.

At a news conference at police headquarters, Chief Philippe Pichet described it as a dark day for the force, adding more officers could also soon be charged.

Faycal Djelidi is accused of a total of nine charges, while David Chartrand is accused of four.

"No one is above the law and police officers are no exception," Pichet said.

Chartrand, 36, and Djelidi, 39, both worked on multidisciplinary investigations and youth co-ordination in the Montreal police's south division.

Pichet

​They were part of a squad that targeted street gangs, drugs and prostitution.

Both are veterans of the force.

Djelidi has been with the department for 16 years and rose to the rank of investigator six years ago. Chartrand has been a police officer for 11 years, and an investigator for the last three.

Pichet said the accusations are related to the way the officers "controlled sources."

Police launched an internal investigation last December after irregularities were flagged, he said.

That initially led to an administrative response, but no corrective action. It was only then that the police department's internal affairs division launched a criminal investigation, according to Pichet.

The police chief said the actions of the arrested officers did not compromise the security of informants or colleagues.

Arrest warrant lays out allegations

Both Chartrand and Djelidi are accused of perjury and attempt to obstruct justice, while ​Djelidi also faces charges of solicitation, breach of trust and obtaining sexual services for consideration.

According to his arrest warrant, Djelidi "solicited" sexual services between May 30 and July 4, and "obtained" them on June 15.

He also encouraged Chartrand to lie during a sworn declaration on June 10 in an attempt to get a search warrant.

A day or two later, Djelidi is said to have approached a fellow officer specializing in sexual exploitation to find out if he was under investigation. This is the basis of the breach of trust charge.

In addition, he allegedly tried to interfere with an RCMP officer on June 21 during an investigation at an apartment building in the north end of Montreal.

Both officers have been suspended without pay.

'It's not a good day for us'

Pichet said two other officers were also arrested, but refused to provide their names.

He also wouldn't say in what division of the force they work or what charges they could face.

The investigation is ongoing and Pichet said there could still be more arrests.

"We have to follow some rules when we are police officers," he said.

"It's not a good day for us as a police department, but in one part it's just a little number of officers that are breaching the rules."

A spokesperson for Public Security Minister declined to comment, saying only that "no one is above the law."

The Montreal Police Brotherhood also declined a request for comment.