Los Angeles, Jul 12 (IANS): Late singer Whitney Houston's mother Cissy Houston says allegations that her superstar daughter and her son were molested by her niece are "unfathomable."

In a statement to people.com on behalf of herself and sister singer Dionne Warwick, Cissy said that they first learned of the claims two days before the documentary titled "Whitney" by Oscar-winning director Kevin Macdonald, premiered in May.

In the film, Whitney's longtime assistant said the singer told her that cousin Dee Dee Warwick molested her as a child and Whitney's oldest brother also made the same claim.

In the statement, Cissy says Dee Dee Warwick may have had her "personal challenges", but the idea that she would have molested her children is "overwhelming and unfathomable."

These are charges "neither Whitney nor Dee Dee are here to deny, refute or affirm … How can that be fair to my daughter, to Dee Dee, to our family?" she added.

The claim comes by way of Mary Jones, Whitney's longtime assistant, who says in the film that the singer opened up to her about the abuse, and would sometimes ask, "Do you think I did something to make her think I wanted her?"

Warwick died in 2008. Whitney died in 2012.