By Jen Heger - Breaking Celebrity News Legal Editor

Law enforcement officials found Lorazepam, Valium, and a sleeping medication in Whitney Houston's hotel room, Breaking Celebrity News is exclusively reporting.

The singer was found unresponsive by members of her entourage on Saturday afternoon at the Beverly Hilton Hotel and she was declared dead by responding paramedics at 3:55 p.m. PST on the eve of the Grammy's.

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 tells us.

PHOTO: Crime Lab Van At The Beverly Hilton Hotel

The prescription drugs were officially taken into custody by the Beverly Hills Police Department, who is handling the investigation, and an autopsy is scheduled to take place either Sunday or Monday.

"Investigators from BHPD will be there when the autopsy is done. This is routinely done in cases when someone relatively young dies and there are no signs of foul play," the insider tells us.