Michael Clarke Duncan died from respiratory failure, according to the actor's newly-released death certificate.
Friends and family members mourned The Green Mile star's passing at a special service in Los Angeles on Monday (10Sep12) and now details have emerged about his death on 3 September (12), weeks after he suffered a cardiac arrest at his home.
Tmz.com reports one of the underlying causes of the actor's death was a severe lack of oxygen to the brain.
Other underlying causes include an irregular heartbeat and acute myocardial infarction (heart attack).