OTTAWA - The federal government has yet to appoint a new full-time chairperson to oversee the Military Police Complaints Commission, raising questions among critics about the future of public hearings into the alleged torture of Afghan prisoners.

It has been a month since the end of Peter Tinsley's tenure as head of the commission, which is looking into what military police knew or should have known about the treatment prisoners captured in Kandahar.

Often-delayed public hearings are set to resume in Ottawa on March 22, but it remains unclear who will be at the helm or whether the military watchdog agency will be forced into yet another postponement.

An interim commissioner, Glenn Stannard, was appointed in mid-December and officials say all the preparations for the inquiry continue.

A spokesman for Defence Minister Peter MacKay said the search for a new full-time chairman is underway.

But Dan Dugas did not say when the process will wrap up -- or whether a replacement will be named in time for the inquiry's resumption.

The chairman is one of two commissioners overseeing the public hearings.

Opposition critics have accused the federal government of sabotaging the Afghan prisoner investigation by refusing last year to reappoint Tinsley, a respected former war-crimes prosecutor, and throwing up a series of legal challenges that have effectively slowed the inquiry to a crawl.

Paul Champ, the lawyer for the human-rights groups that launched the complaint almost three years ago, said federal officials knew last September that Tinsley was on the way out the door and could have been more prepared.

"Why it's taking this long for them to appoint an independent public official to deal with one of the most controversial issues in the country, I don't know," said Champ, who represents Amnesty International and the B.C. Civil Liberties Association.

"One obvious answer is that they're trying to avoid the controversy."

A new commissioner, especially one coming in cold, will have a steep learning curve. The Afghan prisoner investigation is nuanced and complex with its thousands pages of transcripts, jursidictional challenges, national security exemptions and skirmishes over the release of government documents.

Getting up to speed by March 22 will be daunting for a new chairman and if one isn't in place soon the hearings may once again be postponed, said Champ.

"We're getting close to a drop-dead date now and I would say by the end of January, if no one is appointed it's literally impossible for those hearings to proceed at the end of March," he said.

But Ron Lunau, commission counsel, said he's still confident the hearings will take place on schedule and that the absence of a permanent chair would only become a problem if the position was still vacant at the end of February.

If necessary, the hearings could proceed with the acting chairman, but it's "premature" to consider contingency plans, Lunau said.

"We're still expecting to have a full-time chair."

The federal government took the commission to court last year to challenge the scope of its powers -- a legal fight that it won when a Federal Court justice ruled the agency didn't have the mandate to examine the government's overall policy of transferring suspected Taliban fighters to Afghan custody.

The two sides have also fought regular battles over the disclosure of documents from both the defence and Foreign Affairs Departments.

The commission received a slow but steady flow of information before it decided to hold public hearings. And then for over a year after Tinsley called the inquiry, not one report was released by the federal government.

The documents are moving again, according to letters obtained by The Canadian Press.

The commission has set a deadline of Jan. 22 for federal lawyers to deliver the first stage of documents.