Paul Walker died from the "combined effects of traumatic and thermal injuries".
The Fast & Furious star was involved in a fiery car crash in Valencia, California last month (13), when the Porsche his business partner Roger Rodas was driving crashed into a tree and burst into flames.
Walker's death certificate has now been obtained by editors at TMZ.com, and it confirms he was not killed by the impact of the crash alone, but was burned to death once the car exploded.
The Los Angeles County Coroner reports that Rodas died from "multiple traumatic injuries", but unlike Walker, the fireball which engulfed the vehicle was not a factor in his death.
The certificates for both Walker and Rodas also reveal that their deaths were "rapid". An investigation into the cause of the crash is still ongoing.
Walker was laid to rest following a private funeral service at the Forest Lawn Memorial Park in the Hollywood Hills on Saturday (14Dec13).
Over 200 friends and family were in attendance, including his parents, Paul and Cheryl Walker, brothers Caleb Walker and Cody Walker, and Fast & Furious co-stars Tyrese Gibson, Ludacris and Michelle Rodriguez.