Quebec's corruption probe is scheduled to resume its public hearings today after breaking for the holidays.

Today's first witness will be Guy Gionet, former chief executive of the Quebec Federation of Labour's real estate investment fund. 

The commission led by Justice France Charbonneau has so far focused on corruption in the construction industry, illegal party financing and the ties between unions and organized crime.

Former Federation of Labour (FTQ) president Michel Arsenault is expected to testify in the coming weeks. 

Arsenault resigned as president of the union federation in November after it was alleged that he knew about ties some union leaders had to the Hells Angels, but did nothing about it.

Over the course of 2013, the inquiry also put a number of powerful personalities and politicians in the hot seat, including then-interim Montreal mayor Michael Applebaum and former Laval mayor Gilles Vaillancourt.

It's unclear what the commission will focus on this year.

Charbonneau said in December the probe will continue looking at organized crime in the construction industry in January before turning to other topics.

She must submit an interim report to the Quebec government by the end of this month and a final report in April 2015.

With files from CBC News