Israel's state prosecutor has ordered an investigation into Prime Minister Ehud Olmert's role in the 2005 privatisation of Bank Leumi.
Israel has been racked in recent months by a string of corruption scandals allegedly involving top officials.
Police suspect that appointments to the Israeli Tax Authority – including that of its chief Jacky Matza – were influenced by powerful businessmen in exchange for promises of favourable tax treatment.
Both Mr Matza and Mr Olmert's personal secretary and close aide of 30 years, Shula Zaken, have been placed under house arrest in the case, and at least 15 other ITA officials are currently under investigation.
Earlier today Israeli media reported that a criminal investigation could be launched into alleged abuse of influence by the Prime Minister when he was acting finance minister in 2004, during the privatisation of Bank Leumi, which is Israel's second largest lender.
Mr Olmert has denied any wrongdoing.
