The Quebec commission looking into allegations of corruption in the province's construction industry may have to wait until late April before it knows if the RCMP will have to hand over documents it's seeking.

The RCMP's refusal to share with the Charbonneau commission information from its investigation into the Mafia landed the federal agency and the commission in Quebec Superior Court on Monday.

The Charbonneau inquiry wants to see all the proof collected during Operation Coliseum, a major police crackdown in 2006 that rounded up more than 100 alleged Mafia members.

In a court document, the RCMP argues the commission doesn't have jurisdiction over the federally regulated police force.

It claims the commission is on a fishing expedition.

But commission lawyer Sylvain Lussier argued the RCMP can't make a blanket refusal to turn over all files.

"[Any refusal] has to be specific to certain items which would endanger – for example – national security," Lussier said. "But you can't just say, 'I'm not turning it over, and I'm not subject to your jurisdiction.'"

Both sides are scheduled to return to court on April 19, so a judge can determine who is right. Lawyers for both say they hope to reach a compromise before then, but neither side is certain that that will happen.

The commission's chair, Judge France Charbonneau, released a videotaped statement last month calling on the public to anonymously provide tips.

Charbonneau said the inquiry will get underway in May, though it's unclear when it will start hearing witnesses.