TMZ has obtained the 911 call placed moments after Whitney Houston's body was discovered in a bathtub at the Beverly Hilton hotel on February 11.
The caller -- who IDs himself as a member of the Beverly Hilton security team -- informs the 911 operator about a "46-year-old female found in the bathroom."
He adds, "I'm not sure if she fell or if she was in the bathroom with the water."
The caller says he was alerted to the situation by an "irate" woman who called security from the room ... but he couldn't get much info from her because she kept hanging up.
The security member -- who never identifies Whitney by name -- tells the operator he was under the impression the 46-year-old woman was not breathing.
The 911 operator says emergency personnel would be dispatched to the hotel ASAP ... but it was too late.
As we previously reported, Whitney's official cause of death is listed as "accidental drowning" -- but heart disease and cocaine use were contributing factors. According to the final autopsy report, Whitney may have overdosed.
According to the L.A. County Coroner, Whitney's chronic use of the drug caused a narrowing of her arteries, which resulted in a cardiac event before her death.