The Vatican said it has launched an investigation into two Italian journalists over confidential documents that were leaked to the media.
The information revealed gross financial mismanagement at the heart of the secretive city-state.
Journalists Gianluigi Nuzzi and Emiliano Fittipaldi are being investigated for possible complicity "in the offence of divulging confidential news and documents", Vatican spokesman Federico Lombardi said.
The reporters last week published two explosive books shedding an unflattering light on corruption, theft and uncontrolled spending at the Vatican, basing their claims on leaked classified documents.
They claimed charity money was allegedly spent on refurbishing the houses of powerful cardinals, while the murky Vatican bank continues to shelter suspected criminals.
The Vatican's prosecutors have also opened another investigation after the disclosure of a secret document concerning the Administration of the Patrimony of the Apostolic See (APSA), the Holy See's general accounting office.
Lombardi said the APSA is not under investigation.
The head of Italian investment bank Banca Finnat, Gianpietro Nattino, is, however, suspected of using the organisation for money laundering.
The controversy has evoked painful memories of the 2012 "Vatileaks" scandal centred on documents fed to the media by the butler of then-pope Benedict XVI, which contributed to his shock decision to resign the following year.
The storm prompted the Vatican to introduce new legislation in 2013 that threatens up to two years in jail or a fine of up to €5000 for anyone who "procured illegitimately, or reveals information or documents whose dissemination is prohibited".
The arrests started last week when the Vatican held Italian PR expert Francesca Immacolata Chaouqui and Spanish priest Angel Vallejo Balda for allegedly stealing and leaking the classified documents to the media.
Particularly shocking were alleged wiretaps of the pope's private conversations included in Nuzzi's book, Merchants in the Temple.
In one Francis can be heard saying: "If we don't know how to look after money, which we can see, how can we look after the souls of the faithful, which we cannot?"
Both of the suspected moles served on a special commission set up by Pope Francis to advise him on economic reform within the Vatican to clamp down on unbridled spending.