When Robin Williams committed suicide on August 11th at his Northern Californian home, there were no drugs, alcohol or any other illegal substances in his system at the time, the authorities have announced.

Robin Williams
Williams was alcohol and drug free at the time of his death

On Friday (Nov 7th), the Marin County sheriff's office confirmed that the iconic comedian's cause of death was asphyxia due to hanging. TMZ also reports, he was suffering from anxiety and Parkinson's Disease in the days leading up to his suicide.

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According to the gossip site, who obtained the legal documents, the night before he died, Williams placed several wristwatches in a sock and gave them to an unknown individual for safekeeping. Although the coroner's report concludes the late Hollywood star was sober at the time of his death, he did have four drugs in his system, two antidepressants and two caffeine compounds.

The documents also reveal the authorities asked Williams' wife Susan Schneider if he was into autoerotica. She said he wasn't, but did mention he starred in 'World's Greatest Dad' where his on-screen son died from erotic asphyxiation and the scene was "very difficult and emotional for Mr. Williams."

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The late 63 year-old was found in his bedroom, fully clothed, and gently suspended in a seat with a belt wrapped around his neck, with one end wedged between the door and the frame of his closet. He also attempted to cut his wrists with a pocket knife.

Days after his death, Schneider released a statement that revealed he was dealing with early stages of Parkinson's disease: "Robin's sobriety was intact and he was brave as he struggled with his own battles of depression, anxiety as well as early stages of Parkinson's Disease, which he was not yet ready to share publicly," she said. "It is our hope in the wake of Robin's tragic passing, that others will find the strength to seek the care and support they need to treat whatever battles they are facing so they may feel less afraid."