Quebec construction magnate Tony Accurso is expected to testify at the province's corruption inquiry, now that the Supreme Court of Canada has dismissed his request for an appeal.

The inquiry's commissioners are eager to hear testimony from Accurso, who is believed to be a major player in an intricate corruption scheme in the awarding of municipal contracts.

But Accurso tried to avoid testifying, arguing that he would risk incriminating himself and be prejudicing a separate criminal trial.

On Thursday, Canada's top court said it refuses to hear that appeal, effectively clearing the way for Accurso's much-anticipated testimony.

The Quebec construction magnate was arrested in April 2012 in a sweep by Quebec's anti-corruption unit (UPAC).

He faces a string of charges, including fraud, conspiracy, influence-peddling, breach of trust and two counts of defrauding the government. 

Accurso was arrested once again a year ago, this time for his alleged role in a $3-million tax-evasion scheme.

None of those allegations have been proven in court. 

A date has not yet been set for Accurso's appearance at the inquiry. 

The corruption inquiry continues Thursday with testimony from Marcel Roireau, the president of D.J.L., a Quebec construction firm.