Kevin Costner talks The Bodyguard 2 and Princess Diana

Kevin Costner has opened up about Princess Diana's interest in starring in a sequel to The Bodyguard.

The actor told US TV host Anderson Cooper that he spoke with the late princess about possibly appearing in a follow-up to the 1992 romantic drama, which co-starred Whitney Houston.

"Diana and I had been talking about doing Bodyguard 2. I told her I would take care of her just the same way that I took care of Whitney," he said. "'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.'"

Reports have suggested a sequel featuring Diana would have involved Costner's bodyguard character Frank Farmer protecting the princess' character from the paparazzi, only for their professional relationship to blossom into a romance. However, he added to Cooper that the fact he'd been discussing the project with Diana didn't mean she'd absolutely agreed to do it.

"When she died, she was obviously all over the news. I knew that that was an interesting story that I had, but I never brought that up and a very good reporter, about a year later, somehow heard something and finally came to me and I said, 'Yeah, that was true,'" he recounted.

"Not that she was going to do it: That we were talking about doing it."

The original Bodyguard starred Costner as a security expert who is hired to protect the late Houston's pop star character Rachel Marron from a crazed stalker, but ends up falling in love with her.

He also recounted his friendship with Houston during the interview, adding that although he didn't realise the extent of the singer's battles until her death, those close to her had urged him to contact her.

"There were some people that really love Whitney and a couple of times during the last seven, eight years they asked me if I would write her a letter," he said. Costner said that he did write to Houston twice but he doesn't know if his messages ever reached her.

"I elected to let Whitney have her life after The Bodyguard and she would always be close to me," he said. "She would always be someone I appreciated. I saw pretty much what everybody else saw. But when someone asked me to write a letter, I did. I don't know if those letters were ever read."

Costner was among the mourners who attended Houston's funeral in Newark earlier this year.