An Argentine bishop requested massages from young men studying to be priests and stored pornographic photos on his phone, witnesses testified on Tuesday on the second day of the cleric's trial for sex abuse.

The judiciary in Salta issued a statement summarising the testimony on Tuesday, part of an unprecedented trial in Argentina that is the latest case of alleged sex abuse to rock the Roman Catholic church in one of its Latin American strongholds. The trial is being held behind closed doors.

Gustavo Zanchetta, the former bishop of Oran in the northern province of Salta, has been accused of sexually abusing seminarians, as well as abuse of power and financial mismanagement.

On Monday, he denied the accusations, arguing he had "a good and healthy relationship" with all seminarians and that his accusers seek revenge.

One of the three priests who lodged the first complaints against Zanchetta, Gabriel Acevedo, testified on Tuesday that a local church official stumbled upon photos on the bishop's mobile phone in 2014 showing "pornographic content in which the bishop and some young men appear," according to the statement from the Salta judiciary.

Acevedo testified that Zanchetta had lent his phone to the official for church administration purposes, and the official showed the lewd photos to Acevedo.

The priest said he reported the discovery to the Vatican's top official in Buenos Aires, and Zanchetta was summoned to Rome.

Zanchetta's lawyer did not respond to a request for comment, but in the past, another lawyer who represents the bishop dismissed the photos as false and a "crude photomontage."

A judiciary source who was in the courtroom on Tuesday told Reuters one of Zanchetta's accusers testified that the Vatican believed Zanchetta when he said the photos were falsified, and the cleric "came back to Argentina strengthened."

The Vatican has not commented on the case and has conducted its own investigation.

In 2017, Zanchetta left his job as bishop in Oran to work in the Vatican's financial and accounting office.

Tuesday's testimony also included allegations from an Oran seminarian who said he witnessed massages given to Zanchetta by other seminarians, adding that the bishop was feared and played favourites.

Other witnesses described heavy drinking and anxiety among several of the young seminarians.

Zanchetta's trial is expected to last through at least Friday.