ATLANTA • The makers of a Whitney Houston documentary did not inform the singer's family about a sexual allegation in it, until two days before it made its Cannes premiere.

A source had told the film-makers of the documentary that singer Dee Dee Warwick, who battled addictions all her life and died in 2008, molested Houston when she was a child.

That explosive claim has now led to singer Dionne Warwick - sister of the alleged molester - to break her silence, reported Rolling Stone magazine.

"I have tried to refrain from responding to that. My sister would never, ever have done anything to do any harm to any child, especially within our family," she told Larry King Now in an upcoming interview.

"And for those lies to be perpetuated in this so-called documentary film, I think it's evil. I will never, and I mean this, ever forgive those who perpetuated this insanity," Dionne Warwick added.

Houston died in 2012 after she drowned in a hotel bathtub at age 48. Her mother was also outraged by the claim.

"We cannot reconcile the public's need to know about Whitney's life as justification for invasion of her privacy or the charge against Dee Dee, a charge which neither Whitney nor Dee Dee is here to deny, refute or affirm," Cissy Houston responded last month.