Police spokesman Micky Rosenfeld told reporters more than 100 officers were involved in the searches related to questions surrounding the purchase of Olmert's home and political appointments in the the Industry and Trade Ministry.
Last month, Attorney General Menachem Mazuz ordered the third criminal investigation into the prime minister on suspicion he granted improper political favors while serving as industry and trade minister between 2003 and 2005, Haaretz reported.
Rosenfeld said officers were searching private residences along with the Industry and Trade Ministry, Israel Lands Administration buildings, Postal Authority offices and the Jerusalem City Hall.
Olmert is also being investigated in relation to his role in the sale of Leumi, Israel's second-largest bank, during his tenure as finance minister, the newspaper said.
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