MONTREAL - Quebec's inquiry into construction corruption will have its official launch with an opening statement in May.

It's unclear, however, whether the inquiry will begin hearing witnesses before fall.

Quebec Superior Court Justice France Charbonneau, who will head the commission, says no decision has been made yet about when hearings will begin.

She is issuing an appeal to the public, asking anyone who knows of corruption and price-fixing to come forward with evidence.

She is promising their identity will remain confidential.

In a videotaped statement released today, Charbonneau says the commission will hold hearings in different parts of Quebec in an effort to uncover malfeasance in different areas.

Premier Jean Charest called the inquiry under tremendous public pressure.

The premier spent two years resisting calls for such a probe despite mounting evidence of criminal collusion involving organized crime groups like the Mafia.

The end result was reportedly an increase in the cost of public-works contracts in Quebec.