According to BBC Newsnight presenter Jeremy Paxman's new book, On Royalty, Charles enjoys a boiled egg after a day's hunting but he is fussy about how long it is cooked.
"If the Prince felt that number five was too runny, he could knock the top off number six or seven," Paxman told The Guardian newspaper, which is serialising the book this week.
"The story is not true," said a spokesman for Prince Charles, despite Paxman saying the story's source is one of the royal heir's friends.