Eight people are accused of confining a woman in an apartment and forcing her into prostitution.
Longueuil Police said they had an apartment in Old Longueuil under surveillance as they observed a gang trafficking in firearms and narcotics.
Once they had enough information to justify a search warrant, they moved in, at which point they found a woman in her forties who was in very bad shape.
Police said the woman had been physically abused and sexually exploited.
Officers arrested the group and the force is recommending charges of human trafficking, drug trafficking, uttering threats and unlawful possession of weapons.
Seven of the accused have criminal records.
Five of them have been refused bail and will be detained until the preliminary inquiry phase of their legal trials.
Two of the suspects were granted bail and released until the start of their trial.
One woman, Cynthia Lefebrve, is still at large and wanted by police.