Israeli police arrived at Prime Minister Binyamin Netanyahu's Jerusalem residence on Monday morning to interrogate him over one of several graft cases, Israeli media said.
Multiple Israeli media reports said the premier was to be questioned over a case of alleged corruption involving Israeli telecoms giant Bezeq.
He could for the first time face questions over information provided to police by Nir Hefetz, a longtime Netanyahu ally who has turned state witness.
Netanyahu's wife Sara and son Yair are also being questioned along with Shaul Elovitch, Bezeq's largest shareholder, Israeli media reported.
A police spokesman confirmed "various investigative activities" linked to the probes, without mentioning the Netanyahus by name.
This is the ninth time Netanyahu has been questioned in various cases directly or indirectly concerning him, who says he is innocent and points to leftist
He maintains he is innocent and has denounced allegations against him as a media and police witch hunt.
On February 13, police recommended Netanyahu be indicted in two cases, though the attorney general has yet to decide whether to do so.
In the Bezeq case, Netanyahu is alleged to have sought favorable coverage from Elovich's Walla! news site in exchange for government policies that may have benefited the mogul's Bezeq by hundreds of millions of dollars.