Police say Israeli investigators have left for the US to question people in connection with the corruption probe involving Prime Minister Ehud Olmert. Police spokesman Micky Rosenfeld says the investigators flew to the US on Monday and are expected to be there about two weeks. He had no further details. But Israel Radio reported that the officers will conduct inquiries at offices, banks and hotels in New York, Washington and Las Vegas. The radio station also said they planned to question the prime minister's son, Shaul Olmert. The key witness in the case is Jewish American businessman Morris Talansky. He has testified to giving the premier hundreds of thousands of dollars in cash. No charges have been filed yet in the case, and Olmert denies wrongdoing.