The former butler to Pope Benedict XVI will stand trial for stealing confidential papers and leaking them to the press, a magistrate has ruled.
Paolo Gabriele was arrested in May after police found confidential documents at his Vatican flat.
He has been charged with aggravated theft, including stealing a 100,000-euro (£78,000) cheque, while a computer analyst faces complicity charges.
The Vatican says it will continue to investigate the leaks.
Mr Gabriele admitted he was the source of leaked letters published in a controversial book by an Italian investigative journalist in May.
The bestseller, entitled His Holiness, revealed private correspondence between the Pope and his personal secretary discussing corruption and malpractice among Vatican administrators.
The Vatican called the book "criminal" and vowed to take legal action against the author, publisher, and whoever leaked the documents.
Mr Gabriele told investigators he acted because he saw "evil and corruption everywhere in the church" while the pope was "not sufficiently informed".
As the Pope's butler and personal assistant, Mr Gabriele was one of a select few lay people with access to the papal apartments.
If convicted, he faces up to six years in prison.
The 46-year-old has been living under house arrest at his family's flat in Vatican City, where police discovered a stash of confidential correspondence taken from the Pope's Secretariat of State.
As the Vatican has no jail, Mr Gabriele would probably serve his sentence in an Italian prison under an agreement between Italy and the Vatican, Italian media reported.
The Holy See also accuses Vatican employee Claudio Sciarpelletti, a computer analyst and programmer, of acting as Mr Gabriele's accomplice.
He has been charged with aiding and abetting a crime.
The trial is not expected to start until October at the earliest, court officials said.
Vatican spokesman Federico Lombardi said the Pope, as the sovereign head of Vatican City, could intervene at any time to stop the trial or pardon Mr Gabriele.
The BBC's David Willey, in Rome, says some Vatican observers believe Mr Gabriele may be the scapegoat for a wider conspiracy to smear certain of the Pope's top aides.
The highly sensitive media leaks, dubbed "Vatileaks", have been an evident embarrassment to the Pope, prompting the rare investigation, our correspondent says.
The scandal has dominated the columns of Italian newspapers, filling TV programmes and magazines.
The controversy began in January, when investigative journalist Gianluigi Nuzzi published letters from a former top Vatican administrator begging the Pope not to transfer him for having exposed alleged corruption.
Other leaked documents concerned "poison pen" memos criticising Cardinal Tarcisio Bertone, the pope's number two, and the reporting of suspicious payments by the Vatican Bank.