A Spanish priest and an Italian laywoman who had served on a financial reform commission set up by Pope Francis have been arrested in the probe into yet another leak of confidential information and documents, the Vatican said Monday.

A statement from the Holy See's press office said that Vatican prosecutors on Monday upheld the arrests of the two, who had been interrogated over the weekend.

It identified the woman as Francesca Chaouqui and the priest as Monsignor Lucio Angel Vallejo Balda. He is still a Vatican employee. Both of them had served on a now-defunct commission that had been set up by Pope Francis in 2013 as part of his drive to reform the Holy See's finances.

A Vatican spokesman, the Rev. Ciro Benedettini, said Vallejo Balda is being held in a jail cell in Vatican City. Chaouqui was allowed to go free because she cooperated in the probe, the Vatican said.

Chaouqui "has furnished the maximum cooperation and deposited documents in support of what she declared," her lawyer, Giulia Bongiorno was quoted as saying by the Italian news agency ANSA. Noting that her client was already back home, Bongiorno added "she is sure she will very rapidly clarify her position."

Bongiorno, who successfully won acquittal for Amanda Knox's co-defendant in an internationally watched murder trial, is one of Italy's top criminal lawyers. She didn't immediately answer phone calls seeking further comment.

Chaouqui, on her LinkedIn profile, describes herself as a communications expert who was the only woman, the only under-55-year-old and the only Italian woman on the pontifical commission.

Opus Dei, the conservative Catholic religious movement, expressed "surprise and pain" over Vallejo Balda's arrest. It described him in a statement as belonging to a priestly society linked to Opus Dei, and added it had no information on the case.

"If the allegation turns out to be proven, it will be particularly painful because of the damage done to the church," Opus Dei's statement said.

While Francis is intent on modernizing the Vatican and making its finances more transparent, the arrests were the latest confirmation that scandal and intrigue still swirl, as they have for centuries, through the largely closed world of the tiny city-state's administrative bureaucracy.

Current and past papacy efforts to clean house at the Vatican have sparked resentment and found resistance in the Holy See's entrenched bureaucracy, a perfect combination of factors to foster leaks.

Leaks of confidential documents from Pope Benedict XVI's papers in 2012 led to the arrest and trial of a papal butler and a Vatican computer technician.

"One must keep in mind that the leaking of confidential information and documents is a crime" under a law enacted in the first months of Francis' papacy, the Vatican statement said.

Last week, Italian news reports said the Vatican police were investigating to see who had tampered with the computer of the top Holy See's auditor, Libero Milone, who was appointed a few months ago by Pope Francis.

The Vatican confirmed that there was an investigation into the tampering, but declined to say if that incident was related to the two arrests.

Later this week, two expose books by Italian journalists about the Vatican's finances are being published, and the Vatican on Monday contended that such publications only hamper Pope Francis' clean-up drive.

"Publications of this nature do not help in any way to establish clarity and truth, but rather generate confusion and partial and tendentious conclusions," the Vatican said. "One must absolutely avoid the misunderstanding of thinking that's a way to help the pope's mission."

Without specifying if the latest arrests are linked, the Vatican described the books as "fruit of a grave betrayal of the trust given by the pope, and, as far as the authors go, of an operation to take advantage of a gravely illicit act of handing over confidential documentation."

Some Vatican-watchers have theorized that Benedict decided to be the first pope in centuries to resign largely because he was morally dismayed by the leaks and intrigue behind the Vatican's closed doors and felt that in his advancing years, he wouldn't be up to the task of grappling with the scandals.