Newly released documents show that Jeffrey Epstein attempted to mediate a falling out between Microsoft co-founder Bill Gates and the billionaire’s adviser, Boris Nikolic, in 2013.

The dustup prompted Epstein to write an email to himself alleging, among other things, that Gates and his aides were mistreating him despite having a friendship so close that he said he once helped the tech billionaire procure antibiotics to treat a sexually transmitted infection he'd contracted from “Russian girls."

It’s not clear in the messages whether Epstein is writing on his own behalf or drafting something in the voice of Nikolic, a doctor and investor who was a close associate of Epstein's. Emails reviewed by USA TODAY show Epstein acting as a go-between between Nikolic, who was an adviser to Gates, and someone named Larry Cohen, which is also the name of the head of an organization called Gates Ventures.

The emails show that Gates’ relationship with Epstein, by then a convicted sex offender, went beyond philanthropic ventures. They came to light after previous releases from the Epstein estate that included the tech entrepreneur. In previous releases from the Epstein files, Gates appeared in photos with women whose faces were obscured, in a photo with Epstein’s pilot, and in a photo with the former Prince Andrew taken years before he was stripped of his duties and royal title.