LOS ANGELES, California - The Porsche carrying "Fast & Furious" star Paul Walker may have been doing 160km/h or more when it crashed, killing him and the driver.A coroner's report released at the weekend said Investigators found no mechanical problem with the 2005 Porsche Carrera GT or debris or other problems on the road.'ACCIDENT' RULINGThe street in the industrial estate in Santa Clara, about 50km from central Los Angeles, where the crash happened is a 1.6km loop rimmed by hills and isolated from traffic, especially over weekends. The light pole hit by the car carried a 70km/h speed-limit sign.Roger Rodas, Walker's friend and financial adviser, was driving the Porsche "at an unsafe speed", the report said. Witnesses interviewed by deputies estimated it was doing 160km/h - perhaps more.No alcohol or drugs were found in either corpse.The November 30 2013 deaths were ruled "accidental" and caused by traumatic and thermal injuries, the report said. Both corpses were burned over 100" of their surface.Rodas had fourth-degree burns on his head and neck and severe skull fractures, the report said. Walker had broken bones throughout his body, among them his jaw, an arm, ribs and pelvis."For unknown reasons," the report said, "the driver lost control of his vehicle." The driver's side of the car (the left) slammed into a tree and a light pole, spun and his a second tree on Walker's side and burst into flames.SPEED FACTOR CITEDThe Sheriff's Department had previously cited speed as a factor in the crash but had released no estimate of how fast the Porsche was going.Sheriff's investigators are working with Porsche officials and the California Highway Patrol to determine the speed more accurately. Three data recorders survived the crash and fire and may produce that information.Rodas, 38, and Walker, 40, co-owned an auto racing team. Rodas also was a professional driver who competed in 10 Pirelli World Challenge GTS races through 2013..ROOF THIEVES GUILTYThe accident occurred while Walker was on a break after shooting about half of "Fast & Furious 7" whose release Universal Pictures has now delayed for almost a year to April 2015. Walker still will appear in the film, though Universal has not said exactly how it will handle his unfinished performance.• Also on Friday, two men pleaded not guilty to stealing a roof panel from the wreck as it was being removed by a tow-truck. Anthony Edward Janow, 25, and James Brooks Witty, 18, were charged with grand theft and misdemeanour for destroying evidence and resisting or obstructing a peace officer.They will return to court on February 25 2014.