The Vatican says it has arrested two people, a high-ranking priest and a former employee, on suspicion of leaking confidential documents.
They were members of a commission set up by Pope Francis to help reform Church finances.
Officials believe they passed records of its discussions to journalists investigating Vatican corruption.
The documents form the basis of two new books on the controversial state of the Vatican’s finances.
One of the journalists, Gianluigi Nuzzi, was involved in a previous leaks scandal at the Vatican, when Paolo Gabriele, butler to Pope Francis’s predecessor, Benedict XVI, was found guilty of stealing and copying documents from the Pope’s desk.
Gabriele was given a jail sentence but pardoned by Pope Benedict.
The Vatican has called the latest incident a “serious betrayal of trust”.
Lucio Angel Vallejo Balda, a 54-year-old priest, and Francesca Chaouqui, 33, were both arrested by the Vatican gendarmerie at the weekend.
