Los Angeles - Oscar-winning actor and comedian Robin Williams, has died from suspected suicide after a battle with depression, triggering an outpouring of grief and tributes for one of the most beloved entertainers of his generation.
A statement from Marin County Sheriff's Department said Williams' death appeared to be "suicide due to asphyxia".
A post-mortem is scheduled for Tuesday, followed by further toxicology testing, the statement said.
The 63-year-old star of blockbusters such as Good Will Hunting, Good Morning Vietnam and Mrs Doubtfire was found dead at his home in Tiburon, in California just north of San Francisco, shortly before midday on Monday, police said.
President Barack Obama led tributes to an entertainer he described as "one of a kind", while Hollywood titan Steven Spielberg, a close friend, hailed Williams as a "lightning storm of comic genius".
Described in 1997 by showbiz publication Entertainment Weekly as "the funniest man alive", Williams had in fact been suffering from depression prior to his death, his publicist said.
The comedian himself had spoken openly in the past about his battles with alcoholism and drug abuse.
"Robin Williams passed away this morning. He has been battling severe depression of late," Mara Buxbaum said in a statement on Monday.
"This is a tragic and sudden loss. The family respectfully asks for their privacy as they grieve during this very difficult time."
Wife Susan Schneider urged the father-of-three's millions of fans to remember his talent at making people laugh.
"This morning, I lost my husband and my best friend, while the world lost one of its most beloved artists and beautiful human beings," said Schneider, who became the actor's third wife when the couple married in 2011.
"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."