Quebec's anti-corruption unit is raiding five locations in Montreal today, including both the residence and office of Lachine's borough mayor, Claude Dauphin.
The raids are related to a larger investigation looking into the city's cancelled $355-million water-meter contract.
Investigators also searched the residence of Sammy Forcillo, a former member of Montreal's executive committee and one-time head of water management for the city, as well as the home of former executive committee vice-president Francine Sénécal and the residence of one-time executive committee member Cosmo Maciocia.
In a statement, the borough of Lachine confirmed the mayor's office was being searched and said it is cooperating with investigators.
UPAC spokeswoman Anne-Frédérick Laurence said Montreal police are assisting with the investigation.
"The raids might last all day, depending on the cooperation we receive. No arrests are planned, but people [will be] met by investigators today," Laurence said.
Today's raids mark the fifth time in several weeks that anti-corruption officers have conducted searches in connection to the water meter scandal.
Last week, UPAC raided the engineering firm Dessau's building in downtown Montreal.
In 2009, former Montreal mayor Gérald Tremblay announced the multi-million dollar contract awarded to the private consortium GÉNIeau would be cancelled after a review found irregularities with the tendering process.
At the time, it was the biggest contract ever awarded by the city.