Did Prince William, Harry know about contents of Princess Diana's brother memoir in advance?

King Charles has strongly reacted to Princess Diana’s brother Earl Spencer claims he made in his bombshell upcoming book.

War of words has broken out between King Charles and Earl Spencer after the latter claimed the monarch told him she would be quickly 'forgotten' in the days after her death in 1997.

However, the Daily Mail has claimed that Prince Harry was fully aware of Earl Spencer's new Diana memoir.

The report, citing the royal insiders, has claimed that Spencer and Harry discussed the book during his visit to Althorp with Meghan Markle two months ago.

The report further says Harry was given advance warning about the bombshell book, the first extract of which will be published on the Daily Mail.

But, the Duke has not read Spencer’s book, the source close to him said.

Prince Harry and Charles Spencer reportedly discussed the book, Swan Song: Diana, My Sister, when he stayed at Althorp in July.

The outlet quoted royal expert Chris Ship as claiming, "I know that Harry's aware of what his uncle has written in this book. And we also know that Harry stayed with Charles Spencer when he was over in the summer and had a big family gathering.

"They must have spoken about the fact this was going to come out and the things that he was going to say about his father."

However, other sources claimed that Prince Harry, William and the Palace were not informed about the contents of his memoir because security around the final manuscript was so tight.