VATICAN CITY (Reuters) - An Argentine bishop working in a top Vatican financial department is under preliminary investigation for alleged sexual abuse, the Vatican said on Friday, in what could become another setback for Pope Francis over sex scandals pervading the Church.

Gustavo Zanchetta, 54, the former bishop of Oran in northwest Argentina, had been working in the department known as APSA, a general accounting and human resources office that also manages the Vatican’s real estate holdings in Italy.

In a statement responding to recent reports in the Argentine media, Vatican spokesman Alessandro Gisotti said there were no allegations of sexual abuse at the time Zanchetta began working at APSA in December 2017, about five months after he left Oran.

“The accusations of sexual abuse surfaced this past autumn,” Gisotti said, adding that at the time of Zanchetta’s resignation as bishop of Oran he had tense relations with priests in the diocese, who had accused him of being authoritarian.

Zanchetta could not be reached for comment on the accusations or the Vatican statement, which said he would “abstain from work” in APSA - where the pope had created a new position for him - while a preliminary investigation went ahead.

El Tribuno, a newspaper in Argentina’s northern province of Salta, reported on Dec. 28 that three priests made accusations of sexual abuse by Zanchetta to the Vatican’s ambassador in the capital Buenos Aires. The allegations included abuse of power and mismanagement of finances, according to the newspaper.

The accusing clergy members said the abuses happened within St. John XXIII seminary, which Zanchetta founded in Oran in 2016, according to El Tribuno. The seminary is now slated to close.

The Vatican said the current bishop of Oran had gathered testimony which would be sent to the Holy See’s department that oversees bishops, and if the allegations were deemed credible, Zanchetta would go before a special tribunal.

News of the investigation could not have come at a worse time for Pope Francis, a fellow Argentine.

He has summoned heads of some 110 national Catholic bishops’ conferences and dozens of experts and leaders of religious orders to the Vatican on Feb. 21-24 for an extraordinary gathering dedicated to the global crisis of clergy sexual abuse.

On Thursday, as American bishops were gathered in a retreat to reflect on the crisis in their country, Francis sent them a tough-worded letter saying internal bickering had shredded the Church’s credibility in the United States.

The U.S. Church is still reeling from a grand jury report last year that found that 301 priests in the state of Pennsylvania had sexually abused minors over a 70-year period.