Police have opened an investigation into Israeli Prime Minister Ehud Olmert's role in the 2005 privatisation of the country's second largest bank.
Mr Olmert's approval ratings have slumped
It has been alleged that while finance minister, Mr Olmert tried to help two businessmen wanting to buy Bank Leumi.
He has denied the allegation, the latest in a series of charges of wrongdoing against Israeli politicians.
Mr Olmert has already faced several corruption inquiries, but no formal charges have been filed.
A controlling stake into the Bank Laumi was eventually bought by a US investment group to which the businessmen were unconnected.
Prosecutors first approached Mr Olmert at the end of October as part of a preliminary inquiry into the affair.
"The findings of the preliminary investigation led to the conclusion that there was a sufficient evidence to open a criminal investigation," a statement from the Israeli justice ministry said.
Mr Olmert's office has yet to respond to news of this investigation, which comes as his approval ratings slipped to their lowest since he took office last May.
A poll on Friday suggested support had slumped to just 14%.
Two allies of Mr Olmert are currently on trial: former Justice Minister Haim Ramon is charged with sexual misconduct while Tzahi Hanegbi is charged with making illegal appointments as environment minister.
All deny any wrongdoing.