Relatives of late pop icon Whitney Houston have reportedly been told by coroner officials that the singer died from what appears to be a combination of Xanax and other prescription drugs mixed with alcohol rather than drowning.

Los Angeles County Coroner officials told relatives there was not enough water in Houston's lungs to conclude she drowned, Fox News and TMZ.com, citing family sources, reported Monday. Houston's relatives were told she may have died before her head became submerged.

When paramedics arrived, they found the singer unresponsive in the bathtub, the Los Angeles Times reported. But while her body was found there, one source told the Times that officials were unsure whether she died of natural causes or from something else.

TMZ.com is also reporting that Houston's mother has arranged for the singer's body to be flown back to Atlanta as early as Tuesday.

On Sunday, the Los Angeles County Coroner's Office said  that an autopsy on Houston's body has been completed, but official results have been placed on hold, pending toxicology tests.

Los Angeles Deputy Coroner Ed Winter said at a press conference that the tests could take six to eight weeks to process.

Winter added that the Beverly Hills Police Department had requested a "security hold" on the results of the coroner's investigation, meaning no further details will be made available until the inquiry is complete. He confirmed earlier comments made by police that "no foul play is suspected."

He also confirmed that Houston was found Saturday afternoon in a bathtub in her room at the Beverly Hilton Hotel.

Prescription drugs had been found in the Beverly Hills Hilton hotel room where Houston's lifeless body was discovered Saturday afternoon just hours before a huge Grammy party she was to attend.

Police discovered a half dozen bottles of medication in Houston's room, TMZ reported, adding that family members said Houston had been taking the prescription drug Xanax, which is often used to treat anxiety.

When combined with alcohol, Xanax can cause drowsiness. Houston was reportedly found in her bathtub - TMZ says her head was underwater - and could not be revived by paramedics after being removed from the tub.

No alcohol was found in the preliminary sweep of Houston's room, TMZ reports, but there were multiple reports that Houston had been drinking with friends the night before at the hotel.

Houston had also attended rehearsals for the Grammys on Thursday, coaching singers Brandy and Monica, according to a person who was at the event but was not authorized to speak publicly about it. The person said Houston looked disheveled, was sweating profusely and liquor and cigarettes could be smelled on her breath.

She was also observed behaving "erratically" earlier in the week at a Los Angeles club, according to multiple reports.

Houston's body was removed from the hotel early Sunday morning, hours after the Grammy awards party she was there to attend had taken place four floors below her room.

Once pop music's undisputed queen, her voice and image had been ravaged by decades of drug use, erratic behavior and a tumultuous marriage to singer Bobby Brown.

Houston's death on the eve of the Grammy Awards sent shock waves through the music industry, with many stars expressing shock and sadness.