Embattled Bank of Italy governor Antonio Fazio is reportedly under criminal investigation in connection with a high-profile banking scandal.
Mr Fazio has been under pressure to resign
Magistrates are planning to question Mr Fazio next month about his handling of a controversial takeover bid, Reuters and the Financial Times said.
Senior Italian politicians have called on Mr Fazio to quit, but the Bank of Italy has given him renewed backing.
Mr Fazio has denied wrongdoing and said he intends to remain in office.
Under Italian law, being placed under criminal investigation does not imply guilt or mean that charges will necessarily be brought.
According to judicial sources quoted by Reuters, Mr Fazio has been under investigation since August, soon after the scandal first broke.
Reuters reported that magistrates were investigating Mr Fazio for suspected abuse of office and would interview him on 5 October.
However, Mr Fazio's lawyer said his client had not received a summons to appear before magistrates.
Magistrates are investigating a range of suspected criminal activity in relation to the takeover of Italy's Banca Antonveneta.
Mr Fazio has come under pressure to resign following allegations that he tried to stop Dutch bank ABN Amro acquiring control of Antonveneta by favouring a bid from Italy's Banca Popolare Italiana.
Leaked transcripts of telephone conversations seemed to indicate that Mr Fazio had tipped off Popolare Italiana's boss about the Bank of Italy's decision to clear the bid.
Prime Minister Silvio Berlusconi has claimed that the governor's continuation in office is "not compatible with national credibility", but has admitted that he does not have the power to oust him.
On Thursday, the Bank of Italy's board said most members had offered "expressions of faith" in the governor.
"For us at this point, the Fazio case is closed," council member Paolo Emilio Ferreri told Reuters.
Silvio Berlusconi says he has tried to persuade Mr Fazio to step down
Thursday's meeting was considered vital to Mr Fazio's future, since only the bank's superior council has the power to remove him.
However, most of the council's members - drawn largely from business and academia - are believed to be close to the governor.
Mr Fazio was appointed for life and the Bank of Italy is independent of government.