Judgement reserved in Pell appeal against child sex conviction

The fate of jailed Australian Cardinal George Pell was in the balance Thursday as judges adjourned to deliberate over an appeal against his conviction on historical child sex abuse charges.

The three judges in Victoria state's Supreme Court heard two days of arguments by Pell's lawyers demanding his December conviction be quashed, while prosecutors insisted the jury verdict against the one-time top Vatican official was "unimpeachable".

The judges can decide to reject the appeal, order a retrial or acquit Pell, the Catholic Church's most senior convicted child molester. There was no indication of when their ruling would be handed down.

Lawyers for Pell, who turns 78 on Saturday, raised 13 objections to his conviction on five counts of sexual abuse for the assault of two 13-year-old choirboys following Sunday Mass in the 1990s.

Their appeal maintains that the case against Pell was unreasonably dependent on the testimony of a single victim -- the second choirboy died in 2014 -- and fell short of proving his guilt "beyond a reasonable doubt".

The former Vatican number three, who controlled the Holy See's vast finances and was involved in the election of two popes, was sentenced in March to six years in prison.

He was accused of sexually abusing the two choirboys in 1996 and 1997 in the sacristy and hallways of St Patrick's Cathedral when he was Archbishop of Melbourne.

Pell's defence team argued during the first day of the appeal Wednesday that it was "physically impossible" for the cleric to have committed the crimes in a crowded cathedral following Sunday services.

"The verdicts represent a disturbing failure of our jury system," Pell's team said in their submission. "The verdicts should be quashed." "I've said before in judgements that I think juries almost always get it right," responded Justice Weinberg, before adding, "The word is almost."