Probe 'will need many leaders'

Multiple royal commissioners will need to be appointed to oversee the investigation into child sexual abuse because of the breadth and depth of the allegations, a legal expert says.

"I suspect if this is going to be conducted in a timely manner - and by that I mean over the course of a couple of years - it's likely they will need more than one royal commissioner," Professor George Williams said.

Prime Minister Julia Gillard has said she would be prepared to have more than one commissioner.

Professor Williams said a retired High Court, Federal Court or Supreme Court judge would likely head the commission.

"For something like this you need someone of the highest integrity and credibility, someone who has got a forensic mind to sift through information of a very large volume and someone experienced in dealing with witnesses and collecting evidence," he said.

Professor Williams would not nominate candidates but said there was a big pool of judges.

He said other commissioners could be drawn from child protection and psychology fields and a former Federal police commissioner could provide a law enforcement perspective.

Some possible commissioners may include former AFP commissioners Mick Palmer and Mick Keelty, who have led government inquiries since their retirements from the force.