UPAC, Quebec’s anti-corruption unit, is carrying out raids at five addresses in Montreal Wednesday morning.

Four of the addresses are for private residences. About 50 police officers are involved in the operation.

UPAC won't say what investigation the raids are linked to, but reports suggest they are linked to the city’s botched water-meter contract.

The $355-million contract was cancelled in 2009 after the auditor general found problems with how it was awarded.

There were police cars outside a home on de la Visitation St. in downtown Montreal that belongs to former Montreal executive committee member Sammy Forcillo. Forcillo was the executive committee member responsible for infrastructure and water management at the time the contract was awarded.

Police were also present at Lachine Mayor Claude Dauphin's home and at Lachine City Hall Wednesday.

The borough issued a news release saying employees and management "obviously offered their full collaboration in order to help investigators during the unexpected visit."

The release said the borough would not be commenting further in order to avoid compromising the investigation.

UPAC said there have been no arrests nor will there be any arrests as a result of Wednesday's operation.

The anti-corruption squad has carried out raids related to the water-meter contract throughout the month of July, including at Frank Catania Construction, Dessau and engineering firm BPR.