04/11/2012 02:26 pm ET

Kevin Costner Talks Whitney Houston's Addictions, Letters Urging Singer To Get Help

Although few were entirely shocked, fans and family were still saddened to hear that cocaine played a part in Whitney Houston's death. Now, the legend's "Bodyguard" co-star, Kevin Costner, is detailing his relationship with the troubled star, saying that he urged her to seek help in two letters he wrote Houston.

“There are some people that really love Whitney, and a couple times during the last seven, eight years, [they] asked me, would I write her a letter?” Costner told Anderson Cooper in an upcoming May episode of "Anderson." "She would always be close to me, she would always be somebody I appreciated ... I don’t know if those letters were ever read.”

Costner, who was among those who spoke at Houston's New Jersey funeral in February, tells Cooper that while filming "The Bodyguard" with the singer, he had no knowledge of any drug use. Costner remembered Houston's strength and talent at her funeral:

"Whitney, if you could hear me now, I would tell you, you weren't just good enough, you were great. You sang the whole damn song without a band. You made the picture what it was. A lot of leading men could have played my part, a lot of guys could have filled that role. But you Whitney, I truly believe, were the only one who could have played Rachel Marron at that time. You weren't just pretty. You were as beautiful as a woman could be. And people just didn't like you, Whitney. They loved you."

The celebrated film not only put Costner in close proximity to music royalty, but also to the real deal. Coster told Cooper that he had courted Princess Diana to star in a "Bodyguard" sequel.

"She wanted me to write it for her," he said. "I said 'I'll tailor it for you if you're interested.' She goes, 'I am interested.'"

The first draft of the script was sent to Costner the day before Diana's 1997 fatal car crash in Paris.



Remembering Whitney Houston