Billionaire philanthropist Melinda French Gates has said her ex-husband, Microsoft co-founder Bill Gates, being named in new files relating to the late sex offender Jeffrey Epstein dredged up "painful times in my marriage".

She told an NPR podcast she felt "unbelievable sadness", and that "whatever questions remain" needed to be answered by those named in the records, including her ex-husband.

"I am so happy to be away from all the muck," she said. The couple divorced in 2021.

Records released by the US Justice Department include an allegation by Epstein that Bill Gates caught a sexually transmitted disease. Gates's spokesperson has called the claim "absolutely absurd".

Bill Gates has not been accused of wrongdoing by any of Epstein's victims, and the appearance of his name in thefiles does not imply criminal activity of any kind.

In a statement to the BBC, a spokesperson for Bill Gates said the Microsoft co-founder had never attended parties with the late financier and had no involvement in illegal activities associated with Epstein.

"While Mr Gates acknowledges that meeting with Epstein was a serious error in judgment, he unequivocally denies any improper conduct related to Epstein and the horrible activities in which Epstein was involved," the statement said.

The billionaire broke his silence on the release of files by the US Department of Justice (DOJ) in an interview with 9News in Australia this week.

He said the interactions with Epstein were limited to dinners and that he did not visit Epstein's island.

"Every minute I spent with him I regret, and I apologise that I did that," Gates added.

In the interview with NPR's Wild Card podcast, Melinda French Gates said, "For me, it's personally hard whenever those details come up, right? Because it brings back memories of some very, very painful times in my marriage."

She added: "Whatever questions remain there of what - I can't even begin to know all of it - those questions are for those people and for even my ex-husband. They need to answer to those things, not me."

US media have reported that, before their separation, which followed 27 years of marriage, Melinda French Gates was upset about her husband's association with Epstein. After their split was announced, Bill Gates acknowledged having had an affair with a Microsoft employee in 2019.

The allegations about Bill Gates were included in more than three million documents released last week by the Justice Department.

Two emails from 18 July 2013 appear to have been drafted by Epstein, but it is unclear if they were ever sent to Gates.

Both were sent from Epstein's email account and returned to the same account. No email account associated with Gates is visible, and both emails are unsigned.

One email is written as a resignation letter from the Bill and Melinda Gates Foundation and complains about having had to procure medicine for Bill "to deal with the consequences of sex with Russian girls".

The other, which begins "dear Bill", complains about Bill Gates having ended a friendship and makes more claims about Bill Gates having tried to cover up a sexually transmitted infection, including from his then-wife, Melinda.

In his interview with Australian media, Bill Gates added that the email was never sent and the contents of it were "false".

Over the years, Bill Gates and his representatives have downplayed his connection with Epstein. He has previously said they only had "several dinners" to discuss a philanthropy project that did not happen.

After the latest allegations, a spokesperson for Bill Gates said: "The only thing these documents demonstrate is Epstein's frustration that he did not have an ongoing relationship with Gates and the lengths he would go to entrap and defame."

They added: "These claims – from a proven, disgruntled liar – are absolutely absurd and completely false."

Many of the documents, emails and photos included in the millions of files released by the justice department last week shed light on Epstein's vast network of celebrities, business chiefs and world leaders - contacts that persisted in some cases even after his 2008 conviction for soliciting sex from a 14-year-old girl.

Epstein died in a New York jail in 2019 while awaiting trial in a sex-trafficking case.