"Whitney had taken Valium, Xanax, and alcohol, which led to her death. The coroner is waiting on final toxicology results to determine which one of the three was the major contributing factor of her demise,” a source close to the situation tells RadarOnline.com. “The coroner will be closely examining Whitney's blood alcohol content at the time she died as well. The sedatives and alcohol will almost certainly be the cause of death, and not drowning. Her heart stopped beating because her respiratory system was suppressed because of the anti-anxiety meds, and combined with the booze it probably happened very quickly before she was found partially submerged in the bathtub."

Four years ago, Whitney Houston's ex-husband, Bobby Brown, planned to sell a tell-all book about his life with the superstar. And although that book was never published, some say Bobby is once again trying to make it happen.

"Back in 2008, the interest in a book on Whitney Houston wasn't that great," a major publisher tells me. "Whitney had fallen off the radar back then ... but now, following her tragic death, the market has changed. Now is the time for a book that details an honest look into the life of Whitney."

But standing in Bobby's way is the confidentiality agreement he signed when his divorce was finalized, plus the impact that a tell-all would have on his daughter, Bobbi Kristina.

American Boy star Estelle, 32, is in talks after Kelly told Simon Cowell she is to focus on her career in the US.

A source said: "Estelle's name is very high on his list now and serious inquiries have been made as to her availability for auditions in May."