MONTREAL - A former executive for Montreal-based engineering giant SNC-Lavalin has been arrested and is being detained in Switzerland, Swiss media reported Sunday.

Riadh Ben Aissa was let go by the company in February after media reports linked SNC to former Libyan dictator Moammar Gadhafi's son, Saadi.

Swiss media reported that Aissa had business dealings with Saadi and that the former exec is accused in Switzerland of corruption, bribery and money laundering in his alleged activities in North Africa.

Aside from its ties to the former Libyan regime, SNC-Lavalin has admitted publicly to tens of millions of dollars in questionable payments.

It acknowledged that $35 million had been earmarked for construction projects but ended up being spent elsewhere. The company didn't specify where.

The RCMP raided the Montreal offices of SNC in mid-April but wouldn't say if the raid was connected to the questionable payments.

Investors last month asked a judge to approve a $250-million class-action lawsuit against SNC-Lavalin, alleging the firm released "materially false and misleading" information about its "code of conduct, legal compliance and internal controls."

The application, which contains allegations that haven't been proven in court, also claims "SNC and certain members of its senior management team were engaged in unlawful activities in Libya ... contrary to the defendants'... statements."