He was mentioned in a 2015 email but the allegations that led to the email haven't been released in full and so it's entirely possible that it was said to discredit the accuser, and the pictures meant to show him "at an underage orgy" are from a not poorly-attended science conference which I'd expect would be too big to keep anything shady hidden, but this is the best source I could find on it: https://www.telegraph.co.uk/world-news/2024/01/04/jeffrey-epstein-stephen-hawking-court-files-claims/