Oscar winning actor Robin Williams has been found dead in his home in California and police are investigating if it was a suicide, The New York Post reported.

Police responded to a call at the 63-year-old's Tiburon home on Monday at 11:55 a.m. after he had been found unconscious and not breathing. He was pronounced dead at the scene at 12:02 p.m.

Though the investigation by the Marin County coroner's office still ongoing, police suspect his death was caused by suicide due to asphyxia. He was last seen alive in his home Sunday night. 

His publicist released a statement that said: "Robin Williams passed away this morning. He has been battling severe depression as of late. This is a tragic and sudden loss. The family respectfully asks for their privacy as they grieve during this very difficult time."

The actor had been attending rehab at the Hazelden Addiction Treatment Center in Minnesota in July after previously being admitted in 2006, according to Mashable. He was married to Susan Schneider and had two children – Zelda Rae, 24, and Cody Alan, 21 – from a previous marriage to Marsha Garces.  

Williams has stared in movies like "Good Will Hunting," "The Birdcage" and "Mrs. Doubtfire." He was nominated for the Academy Award for Best Actor three times and has received two Emmy Awards, four Golden Globes and five grammies. He has two films due out over the next 12 months, including two this holiday season: "Night at the Museum: Secret of the Tomb" and "Merry Friggin' Christmas."