A military watchdog has adjourned public hearings into the alleged torture of Afghan prisoners while lawyers battle over the scope of the investigation.

Peter Tinsley, chairman of the Military Police Complaints Commission, stopped the hearings two hours after they began Wednesday in Gatineau, Que.

Tinsley called the halt after the commission was hit with three government motions seeking an adjournment.

He will rule next week on whether the hearings into complaints filed by two human rights groups will continue while an appeal takes place of a September Federal Court ruling that limited the scope of the commission's work.

Tinsley hinted after the adjournment that there is a chance the hearing may never take place at all.

The commission is looking into what military police in Kandahar knew — or should have known — about the possible abuse of prisoners Canadian soldiers handed over to Afghanistan's notorious intelligence service for interrogation.

Earlier Wednesday, a written statement by Richard Colvin, a diplomat who worked at Canada's provincial reconstruction base in Kandahar in 2006, was sealed under Section 38 of the Canada Evidence Act, which prohibits the release of national security information and punishes violators with up to five years in prison.

Colvin was in Kandahar when Canadian troops first began handing over captured Taliban fighters to Afghan authorities. He signalled to the commission that he had information on what military police knew about alleged torture in Afghan prisons.

Federal lawyers had sought to have him removed from a witness list. They argued before the commission that public hearings should be suspended until the courts ultimately decide the scope of the investigation, which could mean a two-month delay.

National security restrictions

Government lawyers have threatened to impose national security restrictions on every government witness the commission wants to call, and has already placed restrictions on thousands of pages of documents the comission has requested.

"Since March 2008 …when the chair announced that this panel would hold a public interest hearing, the commission has not been provided with a single document by the govenrment," said commision counsel Freya Kristjanson.

The government said witnesses hit by the orders will not be able to testify at public hearings, but it denied that the orders are a kind of intimidation tactic, used to keep witnesses with something to say from appearing.

"Those who make the allegation know nothing about the Section 38 process, and the obligations that are imposed upon me, to act proactively to make sure the horse doesn't get out of the barn," said Alain Prefontaine, the federal government's lawyer.

Meanwhile, the issue came up in question period in the House of Commons on Wednesday with both the Liberals and NDP accusing the government of a coverup.

"What does the government know about what happened in the Afghan prisons that it doesn't want presented to the commission?" NDP Leader Jack Layton asked.

"The government is flouting the law and the federal court by suppressing witnesses and documents. The Conservatives are not serious about allowing the commission to do its work."

Liberal MP Bob Rae noted that it was government lawyers who successfully fought to have Colvin's letter sealed.

"The government today has a reason for not allowing anyone, anyone to review his evidence and his affidavit," said Rae.

"Id like to ask the minister if there is no coverup, who is going to review in an independent fashion the testimony of Mr. Colvin?"

Both Prime Minister Stephen Harper and Defence Minister Peter MacKay rejected the notion of government interference.

"The government has co-operated at every stage with this commission," Harper said. "We'll ensure that all documents and all witnesses to which the commission has a right are heard by the commission."

Added MacKay, "The commission is not politically influenced and it's not under the direction of the government."

With files from The Canadian Press