Whitney Houston Cause of Death Includes Cocaine

The L.A. County Coroner has just released the singer's official cause of death -- accidental drowning -- but added ... there was evidence of cocaine in her system when she died.

As we previously reported, Whitney was found dead in a bathtub at the Beverly Hilton hotel last month and several pills were found on the scene -- including Xanax, Ibuprofen, and Midol.

Investigators found NO EVIDENCE of cocaine in the hotel room.

Law enforcement sources have told us from the beginning they did not suspect foul play -- and believe her death was not a homicide.