Australian Cardinal George Pell was reportedly to return to Rome tomorrow for the first time since being acquitted of sexual abuse charges, just days after a known Vatican rival was ousted.

Pell, 79, a former high-powered Vatican treasurer tasked by Pope Francis to clean up the Vatican's finances, spent more than a year in prison before he was acquitted and freed by Australia's High Court in April.

He has not been back to Rome since leaving in mid-2017 to face charges for assaulting two choirboys in the late 1990s.

His slated return comes less than a week after the downfall of influential Italian cardinal Angelo Becciu, who was pushed out by Pope Francis on Thursday following accusations of embezzlement and nepotism.

Cardinal Becciu, 72, and six others risk trial in the Vatican on corruption charges, according to the Repubblica daily.

Cardinal Pell was quick to issue a statement thanking and congratulating the pope following Cardinal Becciu's forced resignation.

CathNews, a portal of the Australian Catholic Bishops Conference, said "sources close to Cardinal Pell" had confirmed the prelate, who has been living in his archdiocese of Sydney since his acquittal, was returning to the Italian capital.

The Catholic News Agency said he would set off for Rome tomorrow.

Pope Francis appointed Cardinal Pell in 2014 as an anti-corruption tsar at the Vatican's Secretariat for the Economy. He quickly ruffled a lot of feathers.

"In the months before his departure (for Australia)... Pell clashed in a big way with Becciu. The heart of the matter was two different visions of how Peter's Pence should be managed," the Messaggero daily's expert Franca Giansoldati said.

Peter's Pence is a yearly collection taken up around the world and destined for the poor.

Yesterday, investigative weekly L'Espresso reported that Cardinal Becciu gave financier Enrico Crasso, a former manager of Credit Suisse, control over millions of euros of Vatican investment funds, including from Peter's Pence.

Cardinal Becciu has been linked in particular to a controversial luxury property investment deal in London, with at least some of the money used coming from Peter's Pence.

Mr Crasso also manages an investment fund - Centurion Global Fund - with links to Swiss banks that are being investigated for money laundering scandals, according to the weekly.

The Vatican invested millions of euros into that fund, which lost money, while Mr Crasso and others made millions in fees, Catholic News Agency said.

Pope Francis' surprise decision to not only force Cardinal Becciu to resign but also strip him of the rights associated with being a cardinal - a very rare punishment - came just before a fresh review by Moneyval, according to the Stampa daily.

The anti-money-laundering monitoring body of the Council of Europe, expected in the Vatican this week, is expected to rule whether the Vatican has reformed its finances enough to get onto a "white list" of states that respect international fraud rules.