Prime Minister Ehud Olmert faced a third grilling by police investigators on Friday, the latest development in a corruption case that could force him out of office. Police spokesman Rafi Yaffe said investigators came to Olmert's official Jerusalem residence to conduct the session, which was set to last two hours. The case centers on money he allegedly received from an American Jewish businessman before becoming Israel's leader. Businessman Morris Talansky testified in May that he gave Olmert hundreds of thousands of dollars in cash-stuffed envelopes, and that some of those funds went to fund expensive cigars, hotels and other extravagances. The testimony sparked a public outcry, further tarnishing a prime minister who has faced four previous police investigations since he was elected two years ago. Olmert's political rivals have begun the process of holding internal primaries that could replace him as leader of his party, Kadima, by the end of September. Olmert has denied any wrongdoing but has said he would resign if indicted.