JERUSALEM — He has dominated the Israeli political scene for years, outmaneuvering or outlasting one opponent after another, the ultimate survivor in a system that has chewed up many of his predecessors.

But after a nighttime visit by police investigators who read him his rights before asking him if he was corrupt, Prime Minister Benjamin Netanyahu now faces a new kind of challenge. The opponent who just might sink him is none other than Benjamin Netanyahu himself.

Abraham Diskin, a political scientist at the Academic Center of Law and Science outside Tel Aviv who has advised Mr. Netanyahu, said on Tuesday that it was “not very clear that Netanyahu is going to escape some kind of indictment.” And “once there is an indictment,” Professor Diskin added, “he will have to resign.”

Details of the graft investigation remain murky — “the truth is that we don’t know anything,” Professor Diskin said — but the questions it raises are clear: Could an appetite for high living abetted by wealthy business executives ultimately undercut Mr. Netanyahu as it has so many other politicians in Israel and around the globe?