Billionaire investor Leon Black walked out of a closed-door hearing with the congressional committee investigating late sex offender Jeffrey Epstein after refusing to answer questions on non-disclosure agreements (NDAs), say lawmakers.

Black, whose name comes up in the Epstein files released by the justice department, testified voluntarily. But he left after he was asked about NDAs he may have signed, the panel chairman said.

The House of Representatives Oversight Committee issued two subpoenas for Black to share NDAs and give an on-camera deposition under oath.

Black left Apollo Global Management, which he co-founded, in 2021 amid scrutiny over his Epstein ties. He denies wrongdoing.

"We want to know, was Jeffrey Epstein involved in the NDAs?" the committee's Republican chairman, James Comer, said on Friday.

"Was he involved in writing? Was he involved in awarding funds to the women for the NDAs? What was the reason for the NDA? We want to know everything about the NDAs."

Nondisclosure agreements, commonly called NDAs, are contracts where both parties agree to keep information confidential, often as part of a settlement or employment agreement.

Black's attorneys confirmed to the BBC he walked out after his legal team "made their final comments".

The private equity tycoon hired Epstein as a wealth management adviser and allegedly spoke to him about personal matters, including extramarital affairs from which NDAs resulted, according to the BBC's media partner CBS News.

During his brief appearance on Friday, Black reportedly told the committee he had paid Epstein $158m (£120m) for legitimate purposes over the course of their years-long association.

That amount was the subject of a Senate investigation into whether Black had intentionally overpaid Epstein, cloaking money paid for personal reasons in the guise of financial services.

Black's attorneys have pointed out that an internal investigation at Apollo by the Dechert law firm concluded the fees that Black paid to Epstein were for legitimate tax advice.

Like many others who have spoken to the committee as it investigates Epstein's connections to the wealthy and powerful, Black said the disgraced financier had deceived him.

"I knew Jekyll. I didn't know Hyde," he said in his opening statement, a copy of which his lawyer shared with the BBC.

Black continued: "With the benefit of hindsight, I now know, as does the world, that Epstein was engaged in horrific, sordid activities. I feel terrible for Epstein's victims.

"I want to state clearly that I did not know about this nefarious activity until Epstein was charged with trafficking in July 2019."

Black denied ever abusing a woman, or being with an underage woman, or sex trafficking, or paying Epstein for access to women, or being blackmailed by him.

Black's attorney, Susan Estrich, called the subpoenas "a planned political stunt".

"Mr Epstein had no involvement with any NDAs, whether they exist or not," she said, adding that the committee "did not ask a single question about the legitimate payments to Epstein for professional services on tax and estate matters".

Black had a six-year affair with a former Russian model, Guzel Ganieva, which ended in allegations of abuse, according to court records.

According to a lawsuit filed by Ganieva against Black, which was later dismissed, he prepared a nondisclosure agreement in 2015 to secure her silence.

Epstein offered Black advice, including suggesting in an email to his assistant that Black hire former law enforcement officers to approach Ganieva, according to files released by the US justice department.

"Choose method of message delivery, my choice. - two highly respected former ---- fill in the blank, immigration, scotland yard. sfo. . who may knock on her door and present the terms," Epstein wrote.

Estrich, Black's attorney, has dismissed Ganieva's accusation as "demonstrably false". Black himself has previously said he was the victim of extortion.

A judge ultimately dismissed Ganieva's lawsuit, citing the NDA she signed and about $9m that she had received in the years after entering the agreement.

The House Oversight Committee's top Democrat, Robert Garcia, said in a statement that Black had "stormed out" of Friday's transcribed interview when asked about NDAs.

"Leon Black had a chance to do the right thing and help us bring justice to the survivors," Garcia said.

"Instead, he ran out of the room when he was pressed for information about his non-disclosure agreements with women and his relationship with survivors of Jeffrey Epstein."

Black "will be held accountable if he doesn't comply with our investigation", Garcia added.