Jeffrey Epstein blamed "Charles" on the day Andrew Mountbatten-Windsor lost his UK trade envoy job.
On 21 July 2011, the day it was announced that the former prince would step down from the role, Epstein wrote, "I assume he knows that this is Charles doing".
The email was in response to a message from an associate, who said: "Lots of TV coverage on PA and always big feature on you. Insane."
Sky News believes PA refers to Prince Andrew.
The former prince served as the UK's special representative for international trade and investment between 2001 and 2011. The role gave him access to senior government and business contacts around the world.
He stepped back from the role amid increasing scrutiny and criticism about his continued relationship with the US financier and convicted sex offender.
A photo of the two men walking in New York made headlines in the months ahead of him stepping down.
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The three million files released by the US Department of Justice provide a glimpse into fragments of personal conversations that were occurring when Andrew and Epstein's relationship was making headlines 15 years ago.
The convicted sex offender had been emailing friends about the news Andrew had lost his official trade role all day.
Epstein said, in another email about the news, "I'm sure this is good for him, he will now be free".
He also sent a news article about Andrew stepping down to Ghislaine Maxwell, who asked, "why?" Epstein responded, "I think he wants to make money".
Andrew Mountbatten-Windsor was arrested on suspicion of misconduct in public office on his 66th birthday.
After 11 hours of questioning, he was released under investigation.
Last week in a statement, the King stressed that Buckingham Palace would help the police if it was approached as part of the investigation.
He wrote: "What now follows is the full, fair and proper process by which this issue is investigated in the appropriate manner and by the appropriate authorities.
"In this, as I have said before, they have our full and wholehearted support and co-operation. Let me state clearly: the law must take its course.
"As this process continues, it would not be right for me to comment further on this matter."
Andrew Mountbatten-Windsor has always denied any wrongdoing.
(c) Sky News 2026: Epstein blamed 'Charles' on day Andrew lost UK trade envoy job
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