The mole claims to be one of more than 20 people within the Holy See who have leaked sensitive documents to the Italian media in the last few weeks, in an affair that has been compared to the WikiLeaks scandal and dubbed "Vati-leaks".
The unidentified man, who said he had worked in the Vatican for more than 20 years, made the claims in an interview to be aired on Italian television on Wednesday night. His face was hidden and his voice digitally distorted when he appeared on the TV channel, La7.
According to extracts of the interview, the whistle-blower said the Vatican was engulfed in intrigue, secrecy and a climate of intimidation. "Maybe there is a kind of omerta to prevent the truth from surfacing. Not because of a power struggle but maybe because of fear," he added.
He claimed to have worked in the State Secretariat, which is led by the powerful but unpopular Secretary of State, Tarcisio Bertone, who is reported to have fallen out of favour with the Pope and his supporters.
The whistle-blower said the Vatican is a place where "you can commit a murder and then disappear into the void" – a reference to a murky scandal in the Swiss Guard in 1998, when a young soldier shot dead the corps' commander and wife before apparently committing suicide. The mother of Cedric Tornay, 23, the alleged assassin, has never accepted that her son would have committed suicide and has called on Pope Benedict XVI, 84, to reopen the case, amid speculation that the real killer of the three may never have been caught.