Robin Williams was sober before he committed suicide

An extensive toxicology evaluation confirmed the 63-year-old Oscar-winner, who checked into rehab in June to "maintain his sobriety," had taken prescription medications in "therapeutic concentrations," but there was no alcohol or no illicit drugs in his bloodstream.

The late star's wife Susan Schneider previously dismissed rumours the actor, who battled depression and addiction for much of his life, had fallen off the wagon before taking his life, but confirmed he had been struggling with a few private issues.

Shortly after his death, she said: "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. 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."

The 'Good Will Hunting' star is also survived by his three children from previous marriages, Zak Williams, 31, Zelda Williams, 25, and Cody Williams, 22.