The singer's February 11 death in her suite at the Beverly Hilton Hotel on the eve of the Grammy Awards was an accident, the coroner said Thursday.
"She must have collapsed in the tub, and she then went under the water surface," coroner spokesman Craig Harvey said. "We know she was alive under water because we have all the elements of drowning."
"We know she had heart disease, and we know she was a chronic user of cocaine," he said. "Those two factors combined caused her death as a result of drowning. Were it nor for those two factors, she probably would not have drowned in the bathtub."
While cocaine was found to have contributed to her death, numerous other drugs were found in her body - including marijuana, Xanax and Benadryl - but did not contribute to her death, Harvey said.
"The other medications that were found were either in therapeutic or subtherapeutic levels and are not considered contributory to her death," he said.
Harvey said no alcohol was found in Houston's body.
The report ended weeks of speculation over how the pop star who sang I Will Always Love You had died. Many had speculated that her well-documented troubles with drugs had caused her death at age 48.//DPA