Despite a preliminary autopsy report, the mystery of the singer's sudden passing has yet to be completely solved

By Lanford Beard
March 30, 2012 at 04:00 AM EDT

After weeks of speculation, the L.A. County coroner’s office has ruled on the cause of Whitney Houston‘s death earlier this year, announcing on March 22 that the 48-year-old singer died of accidental drowning, possibly brought on by chronic cocaine use and heart disease. (In addition to cocaine, tests found marijuana, Xanax, Benadryl, and the muscle relaxant Flexeril in Houston’s system; the coroner determined, however, that they did not play a role in her Feb. 11 death, when Houston was found submerged in a bathtub at the Beverly Hilton Hotel on the eve of the Grammys.) The police investigation, meanwhile, is ongoing. Although Houston had long battled substance abuse, the presence of cocaine in her bloodstream does raise some questions: Were any illegal drugs found at the scene? And if not, did a member of her entourage remove them before police arrived? Lieut. Mark Rosen of the Beverly Hills Police Department confirms that the investigation will remain active at least until the complete coroner’s report is delivered in the next several weeks. Beyond that, he would say only, ”It’s our policy not to comment on open investigations.”