The Vatican has hired an international accounting firm to scrutinise the department at the centre of corruption allegations that surfaced in last year’s “Vatileaks” scandal.

Ernst and Young will look at the Governatorato, which runs the day-to-day activities of Vatican City, including its lucrative museums, the Holy See said.

Since assuming office in March, Pope Francis has taken action to tackle years of financial scandals, some involving the Vatican bank, which is being reformed after years of failing to meet international standards against tax evasion and the disguising of illegal sources of income.

The Governatorato is the department where Archbishop Carlo Maria Vigano, the deputy governor of Vatican City, worked before his abrupt transfer to the US after speaking out against what he said was corruption there.

In letters leaked to Italian media by former Pope Benedict’s butler, Vigano complained the department awarded contracts to Italian companies at inflated prices.

In one letter, Vigano said he was shocked to find that in 2009 the Vatican paid about €550,000 to build a larger-than-life Christmas nativity scene in St Peter’s Square.

Vigano said he had managed to almost halve the cost but was subsequently transferred, despite an appeal to his superiors to be kept. He said he was being punished for doing his work too well.

Ernst and Young will deliver its findings to a commission appointed by the Pope to advise him on how to make the Vatican’s financial activities more transparent, the Vatican said.