Prince Andrew faces more "unexploded bombs" over his links to paedophile Jeffrey Epstein.
Palace courtiers fear that King Charles may face more awkward questions about his brother's past despite the Duke of York's insistence that he ended his friendship with Epstein in 2010.
A source told The Sunday Times newspaper: "It feels like more stuff is going to come out. There are still unexploded bombs."
Andrew was forced to give up his role as a working royal following a calamitous interview on the BBC programme 'Newsnight' regarding his association with Epstein - who was found dead in a New York jail in 2019 - and the King is said to have no desire to bring him "out of the freezer".
Andrew, 63, has only been seen on rare occasions in recent times, appearing alongside other royals at major events such as Queen Elizabeth's funeral and the King's Coronation earlier this year.
Officials close to the monarch have even suggested that the Duke of York presents a bigger issue for the royal family than the rocky relations with Prince Harry and Meghan, Duchess of Sussex.
A source said: "Andrew is more of a long-term problem than Harry and Meghan."
Meanwhile, Andrew's ex-wife Sarah Ferguson suggested last month that he is grief-stricken and "lonely" following the deaths of his parents Queen Elizabeth and Prince Philip.
Reflecting on a discussion she had with Andrew about grief on her 'Tea Talks' podcast, Sarah said: "It was very moving actually and at one stage we both, Andrew and I, just sat quietly under some really beautiful trees and sort of I asked him if he was alright without his mum and dad. He said... ‘It’s lonely, you know.’
"He thinks about it a lot ... it’s sort of like, people process grief in their own way, and it's not just him... he’s human like everybody else."