The investigation, dubbed Project Combative, was started about a year ago to target criminal organizations involved in alleged smuggling and sexual exploitation of young Romanian women.
Officers arrested Marius Miclescu, 38, a man from Montreal's St-Léonard borough, on Wednesday morning.
Police suspect Miclescu was involved in human trafficking in the greater Montreal area.
Cpl. Caroline Letang said police believe the victims came to Canada hoping for a better life, but were forced to work in erotic massage parlours.
Police said the four alleged victims were adults.
Miclescu is expected to appear at the Montreal courthouse Wednesday afternoon to face charges of procuring, human trafficking and living on the avails of prostitution.
Letang said more arrests are expected in the next few weeks.
Earlier arrests include Toronto residents
Miclescu's arrest for human trafficking is the latest of several in recent weeks.
Last September, SerafinCirnaru, 39, of Toronto, was arrested after allegedly planning to smuggle several Romanian families into Canada.
Cirnaru is due to appear in court on Nov. 4 for a bail hearing.
Two other Toronto residents — Mirabela Dumitru, 31, and Lilian Ursoi, 23, are also facing charges in connection with their involvement in the human trafficking network.