A Vatican appeals court on Tuesday convicted a priest of sexually abusing a fellow student while they were both attending a school for papal altar boys.

Partially overturning a first instance ruling from 2021, judges sentenced Fr Gabriele Martinelli to two and a half years' imprisonment, according to a copy of their ruling.

The original trial, which began four years ago, was the first in the Vatican concerning sexual abuse that occurred on Vatican territory.

Martinelli was found guilty of corrupting a minor and fined 1,000 euros (£855) in relation to events that took place during 2008-2009.

There was no immediate comment from the priest.

Martinelli was put on trial for having forced a person known only as L.G. to have sex over a longer 2007-2012 period, while both were enrolled at the Saint Pius X Pre-Seminary.

The institution, formerly based inside the Vatican, houses altar boys who serve Mass in St. Peter's, including for the pope, and are thinking of becoming priests.

In the first instance ruling, the former rector of the pre-seminary, Fr Enrico Radice, was cleared of covering up the abuse due to the expiration of the statute of limitations.

Both Martinelli and Radice consistently denied wrongdoing and accused L.G. of having a personal vendetta against them.

Martinelli was ordained after attending the pre-seminary. In the wake of the scandal that engulfed the institution, Pope Francis decided in 2021 to relocate it outside Vatican walls.