Police in California have defended their decision to release details about how actor Robin Williams killed himself, saying state law required that they be disclosed to the public.

Marin County Sheriff's lieutenant Keith Boyd said the agency would have liked to withhold some of the information, but could not under the California Public Records Act.

During a live televised news conference on Tuesday, Lt Boyd announced that the Good Morning, Vietnam and Mrs Doubtfire star committed suicide by hanging himself, describing in detail how Williams carried out the act and the condition of his body. Some have said the level of detail was too much.

Lt Boyd said the sheriff's office would probably also have to release the emergency call it received from Williams' home reporting his death.

Father-of three Williams, 63, was discovered unconscious by his personal assistant on Monday morning at his home in Tiburon, in the San Francisco Bay area.