Whitney Houston's autopsy was completed Sunday, but details about her cause of death are being withheld until her toxicology report is completed, which could take up to six to eight weeks.
Houston, 48, may have fallen unconscious in the bathtub of her Beverly Hilton hotel room, then slipped underwater and drowned, according to published reports. Officials said there were no visible signs of trauma or foulplay.
It's unknown for long Houston was alone in her tub, but she was discovered by either her hairdresser or a bodyguard, who pulled her out of the water, according to TMZ.com, which added that Houston's head was underwater when she was found.
Police were called at around 3:43 p.m. PST, and fire department personnel who were already at the location responded immediately. Houston was in her fourth-floor room but was unresponsive to CPR, and she was pronounced dead at 3:55 p.m.
Beverly Hills police declined to elaborate on the investigation, but RadarOnline.com reported that while no illegal drugs were found in Houston's room, a bevy of prescription sleeping pills were discovered, including Xanax and Valium. Police declined to comment on the report.
Radar also reported that police have unofficially ruled out suicide and are looking at the death as a possible accidental overdose, but police declined to comment on that.