Formerly the top Catholic cleric in Australia, Cardinal 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.
Pell, who accompanied Ridsdale to court in 1993 when he admitted widespread abuse, has repeatedly denied knowing about any of the offences, helping move the priest to another parish or that he tried to bribe a victim to keep him quiet.
That victim was his nephew, David Ridsdale, who alleged he confided in family friend Pell about the assaults and that he was asked by him what it would cost to buy his silence.
Other victims had demanded Pell, who was appointed by Pope Francis in February 2014 to make the Vatican's finances more transparent, return to give evidence to The Royal Commission into Institutional Responses to Child Sexual Abuse.
The cardinal said last week he was willing to do so and on Monday the commission officially requested he appear in person when the inquiry next meets in the Victorian town of Ballarat, at a date to be determined.
"The chair has received a letter from Cardinal Pell indicating that he is prepared to come to Australia to give evidence," the commission said in a statement.
"The royal commission will ask him to give evidence in the second of the Ballarat hearings."
Peter Saunders, 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 not only had a moral obligation to return but should be removed from his Vatican role.
He alleged in an interview with Australia's Channel Nine that Pell hadacted 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," added Saunders, a British survivor of child sexual abuse.
"And I think it's critical that he is moved aside, that he is sent back to Australia, and that the Pope takes the strongest action against him."
'Imperative Pell returns'
A statement issued by Pell's office said the allegations were "false and misleading".
"From his earliest actions as an archbishop, Cardinal Pell has taken a strong stand against child sexual abuse and put in place processes to enable complaints to be brought forward and independently investigated," it said.
"Cardinal Pell has never met Mr Saunders, who seems to have formed his strong opinions without ever having spoken to His Eminence."
The statement added that "in the circumstances, the cardinal is left no alternative but to consult with his legal advisers".
Francis Sullivan, head of the Truth, Justice and Healing Council, which is coordinating the Catholic Church's response to the inquiry, said Pell should return so "we get to see everything laid out in full".
"Until we can get to that point, then all of the commentary around this will continue to swirl without us landing on what really happened."
The royal commission was called after a decade of pressure to investigate wide-ranging allegations of paedophilia in Australia.
It has heard harrowing allegations of child abuse involving places of worship, orphanages, community groups and schools. Pell previously gave evidence, in person, in March 2014.