The toxicology report added "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 release of autopsy findings Thursday ends weeks of speculation about what killed the Grammy-winning singer on Feb. 11 on the eve of the Grammy Award.
Houston was found submerged in the bathtub of her room at the Beverly Hilton Hotel and her death has been ruled as accidental. Several bottles of prescription medications were found in her hotel room, but coroner's officials said they weren't in excessive quantities.
Beverly Hills police said in a statement there was no evidence of wrongdoing in connection with Houston's death.
Coroner's spokesman Craig Harvey says cocaine and its metabolites were found in Houston's system, and it was listed as a contributing factor in her death. He says the results indicated Houston was a chronic cocaine user.
Houston died just hours before she was scheduled to appear at producer Clive Davis' pre-Grammy Awards bash.
The singer was buried in a New Jersey cemetery next to her father after an emotional four-hour funeral service that was attended by friends, family and superstars such as Oprah Winfrey, Tyler Perry, Alicia Keys, Mariah Carey, Mary J. Blige, Jennifer Hudson and Roberta Flack
Houston, a sensation from her first, eponymous album in 1985, was one of the world's best-selling artists from the mid-1980s to the late 1990s, turning out such hits as "I Wanna Dance With Somebody," `'How Will I Know," `'The Greatest Love of All" and "I Will Always Love You." But as she struggled with drugs, her majestic voice became raspy, and she couldn't hit the high notes.
Interest in her music has skyrocketed since her death, pushing her songs back on to charts and into heavy rotation on the radio.
The Associated Press contributed to this story.
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