An autopsy on the body of Brittany Murphy was completed Monday but Los Angeles authorities said it would be several weeks before the actress's exact cause of death was pinpointed.
Assistant Coroner Ed Winter said an initial examination of the 32-year-old actress's body found no evidence of "trauma" after early reports indicated the "Clueless" star died from heart-related causes.
Los Angeles coroner's said the precise cause of death would only be known in "four to six weeks" when toxicology tests are completed.
The TMZ.com entertainment website earlier reported Murphy was very ill in the hours before her death on Sunday and that multiple prescription drugs were discovered in her home.
Los Angeles Police Department investigators said Sunday foul play was not suspected in the death.
News of Murphy's death comes after a medical drama involving her husband Simon Monjack last month, when an ambulance was called to a Los Angeles airport arrival gate as the couple returned from Puerto Rico.
On that occasion, it was the actress's husband who was rushed to hospital. Reports said the couple had been returning to Los Angeles after Murphy was thrown off the set of a movie and fired for difficult behavior.
Murphy made her name in television sitcoms during the 1990s before grabbing notable roles in "Clueless," "Girl, Interrupted," "Sin City," "8 Mile" and "Happy Feet."
She provided the voice of Luanne Platter in more than 200 episodes of the animated television sitcom "King Of The Hill."
Celebrities meanwhile took to micro-blogging site Twitter to express their grief over Murphy's death.
"Brittany Murphy was an incredible ray of Light to so many people. Her smile was contagious. My prayers are with her family and loved ones," wrote Jessica Simpson.
Lindsay Lohan wrote: "My deepest condolences go out to all of Brittany Murphy's loved ones & may she rest in peace... She was a great talent w/a beautiful soul."
Celebrity blogger Perez Hilton struck a somber note, saying Murphy's death followed a "decade of decadence" in the entertainment world.
"Hollywood loses another bright soul... how many more? A decade of decadence and devastation. Time to wake up," Hilton tweeted.
A series of unidentified friends of Murphy meanwhile told People magazine that the actress had spent years wrestling "insane self-image issues."
"Her weight, her hair, her clothes, her skin, her teeth, everything. She was always so self-conscious," one friend said.
"A lot of her problems were due to poor self image," added another. "She wore extraordinary amounts of makeup, tons of fake eyelashes, got her teeth capped, dyed her hair blonde, lost weight -- she wanted to be a beauty."
