Whitney Houston's death was reportedly caused by prescription drugs and alcohol.

An autopsy on the 48-year-old singer - who was found dead in the bath of her room at the Beverly Hilton Hotel on Saturday - has been completed and Los Angeles County Coroner officials have told her relatives that she did not drown.

Sources told TMZ.com that the coroner did not find enough water in Whitney's lungs to suggest she died in the bath, but they believe her passing was a result of the combination of alcohol, Xanax and other prescription drugs she had taken. It is believed that Whitney's official cause of death will not be released for some time to allow police to complete investigations.

"The Beverly Hills Police Department has requested the Coroner's Office put the results on a 'security hold,' because it could hamper their ongoing investigation," a source told RadarOnline.com.

Whitney's mother reportedly plans to have the singer's body flown back to Atlanta tomorrow now the autopsy is complete.