His arrest comes amid a probe into several corruption scandals that have shaken Quebec's largest city for more than a year and that led the former mayor to resign in November.
Quebec's anti-corruption squad in February raided Montreal city hall, asking employees to leave the building as they searched through files.
Officials with the anti-corruption unit, known as UPAC, said it had gathered evidence of alleged fraud and breach of trust there, as well as at eight other locations, including the offices of several boroughs.
Montreal's former mayor Gerald Tremblay resigned in November after witnesses in a corruption probe linked him to an alleged mafia scheme, in which his party allegedly received kickbacks from construction bids, and said the mayor was aware of illegal party financing and campaign spending.
The commission, headed by Superior Court Justice France Charbonneau, is investigating alleged graft, bid-rigging and kickbacks in the awarding of government construction contracts in the Canadian province.