Former Vatican treasurer Cardinal George Pell lost an appeal against his conviction for sexually abusing two 13-year-old choir boys and will remain in prison for at least another three years, an Australian court ruled Wednesday.

Pell, the highest ranking Catholic worldwide to be convicted of child sex offenses, was sentenced in March to six years in jail after being found guilty on five charges of abusing the two boys at St. Patrick's Cathedral while he was archbishop of Melbourne in the late 1990s.

There was no immediate comment from the Vatican on the court's decision.