'The Fast and the Furious' star was killed alongside his friend, Roger Rodas, when the Porsche they were travelling in smashed into a post in Santa Clarita, California, but his sister strongly denies he was involved in a speeding competition with another car at the time.
Ashlie Walker, 37, told the MailOnline: "They were absolutely not racing, that's a complete lie. It hurts us when we hear these lies and it makes our grief worse and more painful.
"These are irresponsible allegations and people are trying to make out speed and racing was the reason for his death when it was just a terrible accident."
The area where Paul and Roger - who was driving - crashed was known as a popular spot for drag racing, and a spokesperson for the Los Angeles County Sheriff's office has said authorities received a phone call on Sunday (01.12.13) suggesting another car was involved when the 2005 Porsche Carrera GT crashed.
Santa Clarita Valley Sheriff's Station traffic investigators have now ruled out the involvement of a second vehicle. However, it does appear Paul and Roger were breaking the 45 miles per hour speed limit of the road.
A source told website RadarOnline: "Though the investigation is in its early stages, investigators from the Los Angeles Sheriff's Department believe the Porsche was going over 100 miles per hour."