The Pope's chief financial adviser has become the most senior Catholic official to be charged over the Catholic church's sexual abuse scandal.

Cardinal George Pell, Australia's most senior Catholic cleric, was interviewed in Rome by Australian police in October over the allegations, which he denies.

But Victoria state Police Deputy Commissioner Shane Patton said he had been called back to Australia to face "multiple charges in respect of historic sexual offences".

Mr Patton said there are multiple complainants relating to the charges but gave no further details.

"It is important to note that none of the allegations that have been made against Cardinal Pell have, obviously, been tested in any court yet," he added.

"Cardinal Pell, like any other defendant, has a right to due process."

Pell has been ordered to appear before Melbourne Magistrates' Court on July 18th.

Sky News Australia Reporter Ahron Young said there are understood to be up to 10 complainants in the case.

"This has massive consequences for the Catholic Church here in Australia and around the world.

"It is unprecedented in modern times for an archbishop to face these sorts of charges."

Pell to return to Australia

In a statement, the Catholic Archdiocese of Sydney said that the cardinal had been told of the charges and "again strenuously denied all allegations".

"Cardinal Pell will return to Australia as soon as possible to clear his name following advice and approval by his doctor who will also advise on his travel arrangements.

"He said he is looking forward to his day in court and will defend the charges vigorously."

The 76-year-old Pell has previously been accused of mishandling abuse cases while he was archbishop of Melbourne and later of Sydney.

Last year he testified before Australia's Royal Commission into Institutional Responses to Child Sexual Abuse, saying that the Church had made "enormous mistakes" in allowing thousands of children to be abused by priests.

He also admitted that he had often wrongly believed the priests instead of the victims.

He was appointed to his Vatican role in 2014 for a five-year term.

The Catholic church in Australia has not commented on the charges but they are further bad news for Pope Francis who, having promised "zero tolerance" of sex abuse, has since fallen short of dealing with it.

In 2014, the Pope created a commission of outside experts to advise him on how to fight abuse and protect children.

But his credibility was dented after two members - including Irish abuse survivor Marie Collins - left and he scrapped one of the commission's key proposals.

He was also criticised for appointing a Chilean bishop who had been accused of helping to cover for a paedophile. In a video later made public, he described the bishop's opponents as "leftists" and "stupid".

Regarding the allegations against Pell, the Pope said last year: "We have to wait for justice and not make a mediatic judgement, a judgement of gossip, because that won't help.

"Once justice has spoken, I will speak."