The Vatican, which is still struggling with the effects of a worldwide paedophilia scandal in the Catholic Church, discovered two cases of possession of child pornography within its own walls last year, its chief prosecutor said on Saturday.

Gian Piero Milano, whose official title is Promoter of Justice, reported the cases in a 50-page report read to Vatican officials at a ceremony marking the start of the city-state's judicial year.

Former Archbishop Jozef Wesolowski was arrested last September in the Vatican on charges of having paid for sex with children. Credit:AP

The Catholic Church has been hit by scandal involving the sexual abuse of children by priests around the world in the past 15 years.

Pope Francis has vowed zero tolerance for offenders but victims of abuse want him to do more and make bishops who allegedly covered up the abuse accountable.