Pope
© Reuters/Tony GentilePope Benedict XVI waves during his Wednesday general audience in Saint Peter's Square at the Vatican March 14, 2012.

The Vatican has opened an extremely rare criminal investigation into embarrassing leaks of top-level sensitive documents alleging corruption and mismanagement in several of its departments.

The investigation, announced in the Vatican newspaper on Friday, will be carried out by an internal tribunal in a bid to find out who leaked the material.

A separate, administrative investigation will be conducted by the Secretariat of State, which manages Vatican bureaucracy. Pope Benedict had also ordered a "high-level commission" to shed light on the affair, the newspaper said.

The scandal, which has come to be known as "Vatileaks," involves the leaking of a string of sensitive documents to Italian media in January and February, including personal letters to the pope.

The two investigations and the establishment of the papal commission were announced in an interview with Archbishop Angelo Becciu, the deputy secretary of state.

Becciu denounced the leakers as cowardly and disloyal people who took advantage of their privileged position to leak documents "whose privacy they had an obligation to respect". The archbishop said the pope was very "hurt" by the leaks.

Becciu also rejected media portrayals of the Curia, the Vatican's central administration, as being populated by ambitious clerics more interested in advancing their careers than serving the Church.

Criminal investigations are very rare in the Vatican.

One of the most sensational was opened after Cedric Tornay, a 23-year-old Swiss Guard who had been turned down for a promotion, killed his commander and the commander's wife before committing suicide.

The Vatican investigator determined that Tornay had acted in a "fit of madness".

Archbishop Whistle Blower

The leaked documents included letters by an archbishop who was transferred to Washington after he blew the whistle on what he saw as a web of corruption and cronyism, a poison pen memo which put a number of cardinals in a bad light and documents alleging internal conflicts about the Vatican Bank.

The leaks began in January when an Italian television investigation broadcast private letters to Secretary of State Cardinal Tarcisio Bertone and the pope from Archbishop Carlo Maria Vigano, the former deputy governor of the Vatican City and currently the Holy See's ambassador in Washington.

The letters showed that Vigano was transferred after he exposed what he argued was a web of corruption, nepotism and cronyism linked to the awarding of contracts to Italian contractors at inflated prices.

As deputy governor of the Vatican City for two years from 2009 to 2011, Vigano was the number two official in a department responsible for maintaining the tiny city-state's gardens, buildings, streets, museums and other infrastructure, which are managed separately from the Italian capital which surrounds it.

In one letter, Vigano wrote of a smear campaign against him by other Vatican officials who were upset that he had taken drastic steps to clean up the purchasing procedures. He begged to stay in the job to finish what he had started.

Bertone responded by removing Vigano from his position three years before the end of his tenure and sending him to the United States, despite his strong resistance.

Other leaks centre on the Vatican bank, which is trying to put previous scandals behind it.

They included the collapse 30 years ago of Italy's private Banco Ambrosiano in a tangle of lurid allegations about money-laundering, freemasons, the mafia and the mysterious 1982 death of its chairman Roberto Calvi - who was dubbed "God's banker".

The Vatican bank, formally known as the Institute for Works of Religion (IOR), is aiming to comply fully with EU standards on financial transparency in order to make Europe's "white list" by June.