Prosecutors are investigating Bank of Italy Governor Ignazio Visco in a probe into alleged corruption and fraud when the Banca Popolare di Spoleto (BPS) bank was put under special administration and subsequently sold to Banca Desio.
Visco is among eight people being investigated in the probe, who also include three administrators nominated by Italy's central bank and current BPS Stefano Lado, who is vice-president of Banca Desio.
The news of the investigation into Visco and the seven other people was reported by daily newspaper Il Fatto Quotidiano on Tuesday.
The central bank said it was not aware of the judicial probe.
A "well developed" criminal scheme had been used to gain control of BPS at a knock-down price "causing grave economic damage" to shareholders, according to Riziero Angeletti, a lawyer representing around 100 minority shareholders in BPS.
These damages were worth between 300 million and 350 million euros to shareholders, according to bank consumer association Adusbef.
The association urged Italy's prime minister Matteo Renzi to dismiss Visco with immediate effect.
The BPS commissioners appointed by the Bank of Italy had refused a better offer for BPS from a different bidder before it was sold last year, Angeletti also said in the complaint he presented to prosecutors.
The Italian economy ministry's decision to put BPS under special administration was wrong and should not have relied solely on the advice of the central bank, an Italian appeals court ruled late last year.
The Bank of Italy had requested that BPS be put under special administration after an inspection in 2012 found serious irregularities and large capital losses at the small lender.
