The singer's toxicology report was released by the L.A. County Coroner's office Thursday, and stated that "Cocaine and metabolites were identified and were contributory to the death. Marijuana, Alprazolam (Xanax), Cyclobenzaprine (Flexeril) and Diphenhydramine (Benadryl) were identified but did not contribute to the death."
The official ruling contradicts earlier media reports that no water was found in Houston's lungs at time of death and that she had not drowned.
Houston was 48 when she passed away on February 11 at the Beverly Hilton Hotel the night before the Grammy Awards.
As RadarOnline.com previously reported, Houston had "a plethora of sedatives including Lorazepam, Valium, Xanax, and a sleeping medication that was found in her hotel room," a law enforcement source said.
Houston battled an addiction to drugs and alcohol for years but was thought to be back on the road to recovery and had just wrapped filming Sparkle with Jordin Sparks.