The former mayor of Boisbriand is facing fraud charges after an investigation by Quebec's anti-corruption squad.

Robert Poirier was arrested Tuesday and will face charges of fraud, conspiracy to commit fraud and breach of trust.

The Hammer Squad, aka Operation Marteau, said the arrest is linked to another investigation that led to the arrest of seven people in February in the same town.

"There were other arrests and other charges against different people and this is another phase in that investigation," said Sgt. Claude Denis, a provincial police spokesman.

Poirier was mayor from 1998 until July 2005, when he stepped down amid allegations of extortion by a businessman.

Police allege the investigations show a system was in place for years that allowed certain companies and firms to obtain lucrative municipal contracts with inside information from city officials.

In turn, the system allegedly permitted former elected officials in the town to benefit in exchange for favourable decisions in the granting of contracts when they were in power.

Police say city officials allegedly received numerous types of bribes -- including cash, illegal political contributions, gifts and paid vacations.

But authorities have declined to put a dollar figure on the alleged fraud.

In the first case, another former mayor of Boisbriand, an ex-city councillor, a construction boss and four construction industry officials face 28 charges.

The accused are: former mayor Sylvie Saint-Jean; former councillor Claude Briere; Giuseppe and Lino Zambito, who are president and vice-president of the Infrabec construction company; Rosaire Fontaine, an engineer at BPR-Triax; and France Michaud and Gaetan Morin of the Roche consulting firm.

The charges they face include fraud, breach of trust, corruption, extortion, conspiracy and uttering threats.

The case is still before the courts.

Quebec introduced Operation Hammer in late 2009, amid a flurry of corruption allegations that shocked the province. The squad has been involved in a number of arrests since its inception.

Earlier this year, the province put in place a permanent anti-corruption unit -- a 189-member unit tasked with rooting out corruption and investigating allegations of influence-peddling and collusion.

But Jean Charest's Liberal government has resisted calls to hold a broader public inquiry into the corruption allegations involving politicians, organized crime and the construction industry.