Whitney Houston's brother feels "responsible" for introducing her to drugs.

The singer tragically died last year, following an accidental drowning in her hotel bathtub.

Traces of substances including cocaine and marijuana were found in her system.

Her sibling Michael admits he didn’t realise how dangerous drugs could be when Whitney started using cocaine many years ago.

"You gotta understand at the time...the '80s ...it was acceptable," he explained in an interview with US talk show host Oprah Winfrey.

"It's painful...I feel responsible for what I let go so far."

Michael was joined by their mother Cissy, who has recently opened up about her daughter in the touching memoir Remembering Whitney.

The 79-year-old uses the book to express her outrage at Whitney's tragic death and her relationship with the singer’s ex-husband Bobby Brown.

"I'm angry she died alone, in those conditions," Cissy wrote. "I'm still mad about that."

Whitney also left behind her daughter Bobbi Kristina. Cissy made it clear she is concerned about the young girl.

"She's not handling it good," Cissy wrote in the novel. "None of us are. Of course I worry about her. Bobbi Kristina is 19 and if you know anything about a 19-year-old, they think they know it all. It doesn't mean that she is going to follow her [mother's] same path. She could but anybody could. I don't want to jinx her. I'm trying to make sure she doesn't."