The Vatican has moved to defend its finance chief Australian George Pell after he was accused by one of Pope Francis' commissioners for child protection of being "almost sociopathic".

Spokesman Federico Lombardi said Peter Saunders, who called for Pell to be dismissed over allegations he covered up abuse and denigrated victims, was expressing his "personal views" and not speaking on behalf of the commission.

Cardinal Pell, formerly the top Catholic cleric in Australia, has replied to all questions posed by the authorities and his defence "must be considered reliable and worthy of attention and respect," Lombardi told journalists.

Pell has become embroiled in the probe in his homeland which last week heard evidence from paedophile priest Gerald Ridsdale, who abused at least 50 boys over two decades.

The cardinal, who accompanied Ridsdale to court in 1993 when he admitted the abuse, has repeatedly denied knowing about any of the offences, helping move the priest to another parish or that he tried to buy a victim's silence.

On Monday, Australia's Royal Commission into Institutional Responses to Child Sexual Abuse requested he give evidence when the inquiry next meets at a date to be determined.

Pell said he would be present at the hearing.

Peter Saunders, a British victim of child sexual abuse who was hand-picked by the pope six months ago to be one of the church's commissioners for the protection of children, said Pell should be removed from his Vatican role.

He alleged in an interview with Australia's Channel Nine that Pell had acted with "callousness, cold-heartedness, almost sociopathic I would go as far as to say, this lack of care", in his approach towards abuse victims.

"Given the position of George Pell as a cardinal of the church and a position of huge authority within the Vatican, I think he is a massive, massive thorn in the side of Pope Francis's papacy if he's allowed to remain," he said.

A statement issued by Pell's office said the allegations were "false and misleading", and added that the Cardinal would "consult with his legal advisers".

The affair has caused a stir in the Vatican, where conservative, straight-talking Pell - tasked with cleaning up the Vatican's murky finances - has made no few enemies.