LOS ANGELES - Comic actor Robin Williams committed suicide by hanging himself and had no alcohol or illicit drugs in his system at the time of his death, coroners said Friday.
The 63-year-old, known for high-energy, rapid-fire improvisation and clowning, was found dead on August 11 at his home in Marin County, north of San Francisco.
The coroner for Marin County, Robert T. Doyle, said the investigation into his death had concluded, giving the cause as "asphyxia due to hanging" and the manner of death as "suicide."
"Toxicological evaluation revealed the absence of alcohol or illicit drugs. Prescription medications were detected in therapeutic concentrations," it added in a brief statement.
Williams, an Oscar-winner and veteran of movies, stand-up shows and hit television series, was one of Hollywood's most popular entertainers and his death triggered an outpouring of emotion the world over.
A few days after his death, Williams' wife said her husband was suffering from depression and the early stages of Parkinson's disease.
Father-of-three Williams had spoken openly in the past about his battles with alcoholism and drug abuse - and often drew on them in his stand-up comedy routines.
Star of hit films such as "Good Morning, Vietnam" and "Mrs Doubtfire," Williams had last been seen alive the day before his death by his wife Susan Schneider before she went to bed.
She left the house the next day assuming he was still asleep in a separate room in the home in Tiburon.
Williams' ashes were scattered in San Francisco Bay, according to media reports.
President Barack Obama and the US first family joined the outpouring of grief, calling him "an airman, a doctor, a genie, a nanny, a president, a professor, a bangarang Peter Pan, and everything in between."
"But he was one of a kind," Obama said.
Later in August the 66th Emmy Awards paid a heartfelt and somber tribute to Williams, his friend and fellow actor-comic Billy Crystal calling him "the brightest star in the comedy galaxy."