A very senior public servant who is knowledgeable about fund-raising will soon be questioned in the probe against Prime Minister Benjamin Netanyahu, Channel 10 reported on Tuesday.Channel 2 reported that the police were looking into incidents in which contributors to the prime minister visited his wife, Sara, at the Netanyahus’ hotel when the two of them were abroad, and gave her valuable presents.Ha’aretz reported on Tuesday that the police are checking if money was transferred from businessmen abroad to Sara and their son Yair for their personal use.The report said the police were clarifying whether contributions from businessmen primarily from the US were systematically given to Sara and Yair to fund their exorbitant lifestyles.Channel 2 journalist Amnon Abramovich told the radio station Radio Lelo Hafsaka that in addition to police questioning Netanyahu under caution, Sara and Yair will be questioned as well.The police extended the house arrest of Netanyahu’s former chief of staff and fund-raiser, Ari Harow, until Friday after questioning him for more than 10 hours on Monday. He is expected to be questioned for a third time in upcoming days.Senior law enforcement officials told Channel 2 that Harow was honest and fair, and had not provided incriminating information against the prime minister. They said they believed Harow could do so without incriminating himself. While Harow was being questioned, another former Netanyahu aide who was involved in fund-raising was also being questioned. More former aides to the prime minister are expected to be questioned in upcoming days.The Ha’aretz report said the police were trying to find out if Netanyahu’s contributors were promised anything in return for their money, and if so, whether the prime minister was involved and aware of the promises.A source in the police’s national fraud squad, Lahav 433, said she could not confirm or deny any of the reports.Netanyahu and Attorney-General Avichai Mandelblit downplayed the ongoing investigation of the prime minister at the Knesset on Monday.Mandelblit said many press reports about the probe have been inaccurate.The prime minister called the investigation “hot air,” and said there was “nothing at all” to the mysterious allegations against him. He urged prospective replacements not to get too excited about the probe.Zionist Union MK Erel Margalit responded that Netanyahu should not be so confident in the face of what could be a serious criminal investigation against him. Margalit said Netanyahu should suspend himself to deal with the probe.Speaking to Radio Lelo Hafsaka, Margalit called the prime minister “a dragon who harms so many people.” Eliyahu Kamisher contributed to this report.