A top advisor to the Pope has criticised Cardinal George Pell, saying Australia’s most senior Catholic should step down from his position at the Vatican.

Peter Saunders, who was hand-picked by Pope Francis six months ago to work as the Catholic Church’s commissioner for the protection of children, said Cardinal Pell’s position was “untenable”.

Speaking to 60 Minutes reporter Tara Brown, Mr Saunders said the cardinal’s response to victims of of child abuse perpetrated by Catholic priests in Victoria was “cold” and “callous”.

"I personally think that his position is untenable. Because he has now a catalogue of denials – he has a catalogue of denigrating people, of acting with callousness, cold-heartedness."

Cardinal Pell, who is the Head of Finances at the Vatican, has been under fire since fresh allegations emerged last week at the Royal Commission into Institutional Responses to Child Abuse in Ballarat, that he deliberately turned a blind eye to child molestation.

Mr Pell’s history of denials include his acknowledgement in 2013 that he had “probably” been shown a photograph of the slashed wrists of a child abuse victim, after he previously said he had never seen it.

Anthony and Chrissie Foster showed the cardinal the photo of their daughter Emma, who was abused by Father Kevin O’Donnell.

Their daughter Katie was also a victim of the priest. Emma went on to take her own life in 2008.

In a 2002 interview with 60 Minutes reporter Richard Carleton, the cardinal denied he had ever seen the picture, before changing his position two years ago.

“Probably, but let’s put this in context. Now we know that was an attempted suicide, you’ve got to understand, this was a…. the production of this photo was something sudden, I didn’t have a chance for a considered response.

"I fully understood the enormity of the suffering,” the cardinal said.

Mr Saunders, who is a victim of pedophile priests himself, said Cardinal Pell is a “massive thorn” in the side of the papacy of Pope Francis.

“I think it’s critical that he is moved aside, sent back to Australia, and [that] the Pope takes the strongest action against him.

“That man has at least a moral responsibility to fly straight back and to tell the royal commission everything he knows – everything he knows in order to allay the fears that many victims and survivors feel, which is that he’s avoiding facing some very, very difficult truths, which is his past behaviour,” Mr Saunders said.

The commission Mr Saunders leads aims to establish greater accountability and transparency on child sex abuse perpetrated within the Catholic Church. Mr Saunders reports to Pope Francis directly.

Victims called on Cardinal Pell last week to front the royal commission following several claims he ignored warnings about Australia's worst pedophile priest, Gerald Ridsdale, and offered a bribe to a victim to stay silent.

Cardinall Pell has previously signed a sworn statement denying he offered a bribe.

Cardinal Pell said he would co-operate with the investigations and would attend the hearings if he was asked to do so.