Ehud Barak
Ehud BarakFlash90

Former Israeli premier Ehud Barak, who is running in the upcoming elections with his new Democratic Israel party, vowed to fight back Wednesday after criticism over his ties to disgraced US financier and registered sex offender Jeffrey Epstein.

Barak, who recently returned to politics ahead of September 17 elections as a fierce Netanyahu critic, has been the subject of reports highlighting his business ties with Epstein, who has been charged with sex trafficking of minors in the United States.

A report in Britain's Daily Mail showed pictures of Barak entering Epstein's New York residence in 2016, with the Israeli's face partially hidden by a neck gaiter.

Epstein had already in 2009 been convicted as a sex felon and served a 13-month prison term.

Barak told the Daily Beast he was there "for lunch or chat" and "never met Epstein in the company of women or young girls."

In a tweet late Tuesday, Barak rejected the Daily Mail's "despicable insinuations" and threatened to sue the paper.

"I indeed was in his house, I never took part in any party/meeting of the kind hinted to," he wrote.

"I suggest the people at the Daily Mail and anyone cooperating with them to prepare their credit cards. The libel suit is on its way."

Later Wednesday Barak was expected to address the report during a conference of his Israel Democratic Party.

The Daily Mail report was the latest linking Epstein to Barak, whose campaign seeks to depict him as free of corruption in contrast to Netanyahu, who faces possible corruption charges in the months ahead.

Earlier this month, Israeli newspaper Haaretz reported that Epstein, whose 2009 conviction was for soliciting prostitution from a minor, had in 2015 invested in a start-up headed by Barak.

Barak admitted to giving Epstein "a second chance," saying in Facebook posts that the American financier was a "passive investor" and that he was examining ending the affiliation in light of the latest allegations.

Israeli media have also reported on a $2.3 million grant Barak received from the Wexner Foundation, where Epstein served as a trustee, for unspecified research in 2004.