Cardinal George Pell is "a dangerous individual" and "almost sociopathic" in his response to child sexual abuse victims, Pope Francis' specially-appointed commissioner for the protection of children, Peter Saunders, says.

In an interview with Channel Nine's 60 Minutes, Mr Saunders said Cardinal Pell had a "moral responsibility" to front the Royal Commission into Institutional Responses to Child Sexual Abuse and address allegations that he knew of priests abusing children in Ballarat and elsewhere but did nothing to stop it. Cardinal Pell has denied these accusations.

"I personally think that his position is untenable, because he has now a catalogue of denials," Mr Saunders said in the interview, which aired on Sunday night.

"He has a catalogue of denigrating people, of acting with callousness, cold-heartedness – almost sociopathic, I would go as far as to say – this lack of care."