The American boss of one of Britain’s biggest banks is being investigated over his ties to late pedophile Jeffrey Epstein, it emerged Thursday.

Barclays chief executive Jes Staley, 64, insists he only had a “professional relationship” with Epstein — but maintained contact with him for several years, even after he was convicted of having sex with underage girls.

The bank says it challenged Staley over his ties to the perverted moneyman last year when the Epstein scandal blew up after he was charged with further serious sex crimes and ultimately hanged himself. The company concluded that it had no concerns over the way its chief executive characterized the nature and extent of his relationship with the convicted sex offender, the Guardian reports.

That information was used to defend the banker in an initial probe by Britain’s Financial Conduct Authority (FCA), Barclays said in a statement to the London Stock Exchange.

However, the UK’s Prudential Regulation Authority has now joined the FCA in an ongoing investigation, challenging the “characterization” of the relationship, Barclays confirmed.

The Boston-born banker said he “deeply regrets” his friendship with the pedophile, whom he first met in 2000 when he took charge of JP Morgan’s private banking division and Epstein was “already a client” in New York.

“The relationship was maintained during my time at JP Morgan, but as I left JP Morgan, the relationship tapered off quite significantly,” insisted Staley, who spent much of his career in the Big Apple.

Staley said his last contact was in the summer and autumn of 2015, seven years after Epstein was convicted and jailed for sex with a minor. The banker insists he had no further contact after joining Barclays in December 2015.

“Obviously I thought I knew him well and I didn’t,” Staley told reporters of Epstein.

“For sure, with hindsight with what we know now, I deeply regret having any relationship with Jeffrey.”

The board of Barclays said Thursday that it retained confidence in Staley and would recommend him for re-election at the bank’s shareholders’ meeting in May.

Barclays’ annual report shows Staley took home $7.73 million in one year, the Sun says.

Barclays shares were down 2.5% at $2.27 on the London Stock Exchange.

With Post wires