A grey Ford Focus car and a motorcycle were involved in a collision in Rose Kiln Lane at the junction with the Skoda dealership and the casino at around 8.15pm on Friday 18 December.
The motorcyclist, a man in his forties, sustained serious injuries. He remains in hospital in a serious but stable condition.
The driver of the car, a man in his thirties, was uninjured.
Investigating Officer, PC Beth Drummond of the Joint Operations Road Policing Unit, made this new appeal today. She said: “We have now obtained new evidence in the form of dash-cam footage that shows a number of witnesses at the incident, some running towards the scene to help the motorcyclist and driver of the Ford.
“We appreciate that two of these witnesses have come forward but there were other witnesses at the scene who we need to speak to, therefore I would urge them to contact police as soon as they can. The easiest way to do this is by visiting our website or by calling 101, quoting the investigation reference number 43200430959.”