"Diana and I had been talking about doing Bodyguard 2," he told US TV interviewer Anderson Cooper. 'I told her I would take care of her just the same way that I took care of Whitney.
"She let me know that her life might be changing at some point, so she was having her own internal struggles."
Costner said he had kept the discussions secret, but that the conversations leaked after Diana's death in a car crash in Paris in August 1997.
"When she died, she was obviously all over the news," he said. "I knew that that was an interesting story that I had, but I never brought that up.
"A very good reporter, about a year later, somehow heard something and finally came to me and I said, 'Yeah, that was true'. Not that she was going to do it, but that we were talking about doing it." Costner added: "She wanted me to write it for her. I said, 'I'll tailor it for you if you're interested'. She goes, 'I am interested'."
The actor claimed the Royal Family had tried to dispute the story. He said: "And then it came from the Royal Family, some people said, 'No that's not true, that's not true'.
"I called them up and said, 'Don't do that, because it's true. I didn't talk about it when I could have a year earlier and I didn't try to make it a story. Somebody else found this out and I said it was true, so don't say it's not true". And so they said, "OK".'
In an ironic twist, the actor received a draft of the script for Bodyguard 2 on August 31, 1997 - the day Diana died.
Costner also spoke about his former co-star Miss Houston, who was found dead in a Beverly Hills hotel bathroom in February.
The actor said: "There were some people that really loved Whitney and a couple times during the last seven/eight years they asked me would I write her a letter. I did. I don't know if those letters were ever read."
- Daily Mail
