Montreal police have arrested four of their own officers following an internal investigation dating back to 2015. David Chartrand and Faycal Djelidi both face charges that include perjury and attempt to obstruct justice. Djelidi also faces charges of solicitation, breach of trust and obtaining sexual services.

Both worked in multidisciplinary investigations and youth co-ordination in the Montreal police’s south division.

They were part of a unit aimed at cracking down on street gangs, drugs and prostitution.

Montreal police Chief Philippe Pichet said the accusations relate to the way the officers “controlled sources.”

“No one is above the law and police officers are no exception,” he said at a news conference Thursday.

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

Both of them have both been suspended without pay.

Pichet didn’t name the other two officers who were arrested. The investigation is ongoing.

The Montreal Police Brotherhood declined a request for comment.