“I happened to be in England, and I got this message that the prince would love to talk, and I said, ‘What?’… and then I went, ‘Okay,’ ” Costner told People.

“We met in this room, and it was just us. He walked up, and we shook hands… The first line out of his mouth was, ‘You know, my mom kind of fancied you.’

Following that, according to Caras, the two spoke for about half an hour. Costner did not want to reveal all the details of the private conversation, but described his meeting with Prince William as “sweet”.

Years earlier, Costner had reportedly been in contact with Princess Diana over collaborating on a sequel to the hit 1992 film The Bodyguard.

“There was a moment that that was really flying down the tracks, very quietly, because it’s how I operate,” Costner explained, revealing that he had been introduced to Princess Diana by Sarah Ferguson.

“It was so sweet. Sarah was the one that set this up. Sarah was very cool… when she could have been going, ‘Well, I’m a princess too. What about me?’ She didn’t do that at all. Diana and I began to talk.”