A former SNC-Lavalin senior executive accused of fraud in the McGill University superhospital project arrived in Montreal on Wednesday after his extradition from Switzerland.

The head of Quebec's anti-corruption unit said Riadh Ben AissaSNC's former head of construction, was detained by provincial police.

His return came two weeks after Swiss authorities announced they had accepted a deal reached Aug. 4 and sentenced him to the 29 months he'd served in jail. They also ordered him to repay millions of dollars to the company.

In Canada, authorities laid 16 fraud-related charges against Ben Aissa in February 2013 in connection with the new McGill University Health Centre, one of Canada's largest infrastructure projects.

He and several other people, including former SNC chief executive Pierre Duhaime, allegedly committed fraud of $22.5 million in exchange for the company landing the $1.3-billion contract.

Arthur Porter, the former head of the MUHC, remains in a Panama jail fighting extradition to Canada on accusations he was involved in the alleged fraud.

In Switzerland, Ben Aissa was accused of fraud, corruption and money laundering.

The charges stemmed from SNC-Lavalin's business in Libya. Ben Aissa acknowledged in court that he bribed Saadi Gadhafi, son of Libya's late dictator, Moammar Gadhafi, so SNC could win contracts.

Ben Aissa also admitted to pocketing commissions.