The squad targeted the home of Suzanne Bibeau, whose brother Marc Bibeau used to be a key party fundraiser.
The anti-corruption unit says search warrants were carried out this morning north of Montreal but that no arrests are planned.
This latest raid is believed to be connected with another police operation that took place last month.
Two construction companies belonging to the Bibeau family were targeted in those three raids.
Marc Bibeau, who had close links to former premier Jean Charest, was one of the administrators.
About 70 officers took part in the November raids, which involved firms in Saint-Eustache and Laval, north of Montreal.
Investigators questioned 15 people and also seized documents and computers.Suggest a correction