Canberra, Jan 11 : Cardinal George Pell, whose conviction on child abuse charges shocked the Catholic Church before being quashed, has died of heart complications after hip surgery, officials said on Wednesday. He was 81. The former Vatican treasurer is Australia's highest ranking Catholic cleric, and the most senior Church figure ever jailed for such offences, reports the BBC. Cardinal Pell served as Archbishop of both Melbourne and Sydney before becoming one of the Pope's top aides. He was summoned to Rome in 2014 to clean up the Vatican's finances, and was often described as the Church's third-ranked official. But the cleric left his post in 2017, returning to Australia to face trial on child sex abuse charges. A jury in 2018 found he had abused two boys while Archbishop of Melbourne in the 1990s. Cardinal Pell, who always maintained his innocence, spent 13 months in prison before the High Court of Australia quashed the verdict in 2020. However a civil lawsuit -- launched by the father of a choirboy that prosecutors alleged Cardinal Pell abused -- is still under way, the BBC reported. Archbishop of Melbourne Peter Comensoli paid tribute to Cardinal Pell as "a very significant and influential Church leader" while Australian Prime Minister Anthony Albanese said his death would be a "shock to many". Former Prime Minister Tony Abbott praised the cleric as a "saint for our times" and "an inspiration for the ages", saying the charges he'd faced were "a modern form of crucifixion". But Steve Dimopoulos, a government minister in Cardinal Pell's home state of Victoria, was among those who voiced mixed feelings. "Today would be a very difficult day for the cardinal's family and loved ones, but also very difficult for survivors and victims of child sexual abuse and their families and my thoughts are with them," he said. Cardinal Pell also faced criticism in Australia over his role in the Church's response to allegations of child sex abuse. The cleric knew of child sexual abuse by priests in Australia as early as the 1970s but failed to take action, a landmark inquiry found in 2017. /IANS