JERUSALEM — A former Israeli leader who is seeking to topple Prime Minister Benjamin Netanyahu is facing scrutiny over his financial and personal ties to Jeffrey Epstein, the American financier charged with sex trafficking and abusing underage girls.

Ehud Barak, 77, a former prime minister and defense minister, received some $2.3 million in payments from a foundation associated with Mr. Epstein from 2004 to 2006, and Mr. Epstein invested a reported $1 million in a limited partnership established by Mr. Barak in 2015.

Mr. Netanyahu, who is facing possible indictment in three corruption cases involving his relations with tycoons, has demanded an investigation into Mr. Barak’s relationship with Mr. Epstein.

Mr. Barak, a longtime critic of Mr. Netanyahu’s, has denied wrongdoing, said he did not know then about the allegations against Mr. Epstein and accused Mr. Netanyahu’s camp of exploiting the episode to distract from the prime minister’s own legal woes.