Cardinal George Pell, a one-time financial adviser to Pope Francis, died Tuesday in Rome at the age of 81.

Pell suffered fatal heart complications after undergoing hip surgery, according to Archbishop Peter Comensoli, Pell's successor as archbishop of Melbourne. Pell was in Rome for Pope Benedict XVI's funeral last week.

Notably, Pell had spent more than 400 days in solitary confinement in his native Australia on child sex abuse charges before his convictions were overturned.

"For many people, particularly of the Catholic faith, this will be a difficult day and I express my condolences to all those who are mourning today," Australian Prime Minister Anthony Albanese said of Pell's passing.

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Sydney Catholic Archbishop Anthony Fisher told reporters that he was shocked to hear of Pell's death.

"It will be for historians to assess his impact on the life of the church in Australia and beyond, but it was considerable and will be long-lasting," Fisher said.

According to Fisher, a requiem for Pell will be held at St. Peter’s Basilica in the Vatican in the coming days, and his body would eventually be brought back to Australia for a funeral mass and buried in the crypt at St. Mary’s Cathedral in Sydney.

Pell, the former archbishop of Melbourne and Sydney, became the third-highest-ranked official in the Vatican after Pope Francis in 2014 selected him to reform the Vatican's opaque finances.

He spent three years as prefect of the newly created Secretariat for the Economy, where he tried to impose international budgeting, accounting and transparency standards.

Pell spent three years as prefect of the newly created Secretariat for the Economy and attempted to implement international budgeting, accounting and transparency standards.

But he returned to Australia in 2017 to try and clear his name amid child sex charges stemming from his time as archbishop.

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He was initially convicted by a Victoria state County Court jury following accusations that he molested two 13-year-old choirboys at St. Patrick’s Cathedral in the 1990s shortly after he had become archbishop of Melbourne. Pell served 404 days in solitary confinement before the full-bench of the High Court unanimously overturned his convictions in 2020.

The Associated Press contributed to this report.