US actor Robin Williams has been found dead, aged 63, in an apparent suicide, California police say.
Marin County Police said he was pronounced dead at his home shortly after officials responded to an emergency call around noon local time.
Williams was famous for films such as Good Morning Vietnam and Dead Poets Society and won an Oscar for his role in Good Will Hunting.
He had been open in the past about his struggles with alcohol and drugs.
He had recently returned to a rehabilitation centre to "fine-tune" his sobriety, the Los Angeles Times reported in July.
"At this time, the Sheriff's Office Coroner Division suspects the death to be a suicide due to asphyxia, but a comprehensive investigation must be completed before a final determination is made," police said in a statement.
In a statement, Williams' wife, Susan Schneider, said she was "utterly heartbroken".
"On behalf of Robin's family, we are asking for privacy during our time of profound grief. As he is remembered, it is our hope the focus will not be on Robin's death, but on the countless moments of joy and laughter he gave to millions."
Williams had three children from previous marriages.