Porter and his wife Pamela were arrested in Panama on a warrant issued by Interpol.
Porter is accused of fraud, conspiracy to commit fraud and other crimes, the UPAC anti-corruption unit said Monday.
News reports say SNC-Lavalin paid out $22 million to win the contract to build a new McGill University Health Center.
Porter, a respected businessman in Quebec, resigned abruptly in 2011, and was later traced to the Bahamas.
He owns a clinic there. The reasons for his presence in Panama were not immediately known, as in March he said he was fighting cancer.
UPAC was created in 2011 after a series of corruption cases involving the assignment of public works contracts in Quebec.