Quebec's anti-corruption unit is raiding companies that have done business with Hydro-Quebec.

The raids are taking place at nine locations in Laval, Blainville, and elsewhere, most notably the offices of Catania construction.

UPAC says the companies involved cleared snow and performed other maintenance for the provincial utility.

Hydro-Quebec said it was not made aware of the anti-corruption raids until today. However, the utility did an internal inquiry in 2014 which resulted in the firing of an employee for taking bribes.

Hydro-Quebec on Wednesday would not say which company or companies paid bribes back then because that information is part of UPAC’s ongoing investigation. Hydro says it may eventually take action against companies when and if they are found guilty of fraud or other charges.

UPAC said its goal with Wednesday's raids was to gather enough evidence to lay charges, most likely of fraud and corruption.

This is the first time any company that did business with Hydro-Quebec has been subject to an investigation by UPAC.