Detectives investigating the death of singer Whitney Houston have shifted their focus from the Beverly Hilton hotel where she died Saturday and are now looking to examine the prescription drugs found in her room, according to reports.

The Los Angeles Times reported that investigators have ended their work at the hotel and will begin trying to determine if Houston took any drugs that might have caused her death. The 48-year-old star was pronounced dead in her suite at the Beverly Hills, Calif., hotel.

Investigators will continue interviewing people while awaiting the results of toxicology tests. That could take six to eight weeks.

No matter what medication they may be taking, until we do a toxicology test and see the levels, we are not going to speculate, Ed Winter, a spokesman for the Los Angeles County coroner's office, told the Times.

Reports are that authorities collected several bottles of prescription drugs from Houston's suite, among them ibuprofen, Xanax, Midol and amoxicillin.

TMZ reported that not a lot of pills were recovered from the scene. It's unclear whether the pills caused the singer's death, but family sources have told the celebrity news website that Houston died as a result of her medication and alcohol combination.

The Times reported that investigators are expected to speak to Houston's doctors to determine if the singer had any underlying medical conditions.

Houston struggled with drug and alcohol problems for years. She went back to rehab last May.