The provincial tax man is now going after Tony Accurso's companies.
Revenue Quebec is searching nine offices, including multiple companies linked to Accurso, an accounting firm and an insurance broker.
Some of the companies raided include Marton Construction, Simard-Beaudry and Louisbourg Construction.
About 90 investigators are operating in Laval, St. Eustache and Montreal.
Accurso has been arrested twice this year for alleged tax fraud.
In August the RCMP said Accurso and several other people, including former Revenue Canada employee Adriano Furgiuele, had tried to hide $3 million from the federal government.
In April Accurso was arrested as the Surete du Quebec's permanent anti-corruption squad targeted a fraud ring operating in Mascouche, Laval and Terrebonne.
Two Accurso companies, Construction Louisbourg and Simard-Beaudry Construction, had their licences suspended in January after being found guilty of tax fraud.
