LOS ANGELES — Pop legend Whitney Houston may have overdosed on drugs and alcohol before drowning face-down in her bathtub, coroners said, giving grisly details of her shocking death in February.

The 48-year-old was found lying face down in her bathtub in the Beverly Hilton hotel, the Los Angeles County Coroner's office said in a full report on her death.

The 42-page document gave more details than an initial report released last month, which concluded that the Grammy-winning singer died from accidental drowning after taking cocaine, which could have triggered a heart attack.

"The decedent possibly overdosed on a narcotic substance, prescription medications, over-the-counter medications, and alcohol," said the full report, adding that there were no signs of foul play.

It cited the star's personal assistant as having found her lifeless in her hotel room on February 11, hours before a star-studded party on the eve of the music industry's annual Grammys awards show.

"The personal assistant... went into the bathroom, and she found the decedent lying face down in the bathtub, unresponsive. (...) The bathtub was filled with water, and there was water on the bathroom floor," it said.

The report noted that a substance -- which was later determined to be cocaine -- was found in the bedroom.

"Located on the south portion of the counter was a small spoon with a white crystal-like substance in it and a rolled up piece of white paper, along with other miscellaneous items," it said.

Various bottles were found in the hotel room -- in all some 12 different medications, the report said.

It described in gruesome detail the scene when investigators arrived, after the body had been taken out of the bathtub and placed on the bedroom floor -- where the carpet was soaked from water overflowing from the tub.

Efforts to re-start her heart had apparently already been made, the report said, adding there was "a defibrillator patch on the upper right side of her chest and there was another defibrillator patch on the left central portion of her torso."

Houston's sudden death cast a pall over the annual gathering at the Staples Center in Los Angeles, with several tributes to the singer -- and a public prayer -- added to the show at the last minute.

The singer of hits such as "I Will Always Love You" sold more than 170 million records during a nearly three-decade career, but also fought a long battle against substance abuse.

Last month it emerged that Houston had left all of her assets to her daughter Bobbi Kristina, born from her troubled marriage to singer Bobby Brown, who gets nothing.

A few days later Bobbi Kristina said she plans to follow her mother into show business.

Houston's sister-in-law, Patricia Houston, claimed the star's untimely death could have been predicted.

"The handwriting was kind of on the wall. I would be kidding myself to say otherwise," she told TV talkshow queen Oprah Winfrey.