A grey Ford Focus and a black Kawasaki motorcycle collided on the A120 at Tinker Street in Ramsey at around 6.30am on 23 September.
Two occupants from the car and the motorcyclist, a man from the Clacton area, were taken to hospital following the collision.
The motorcyclist remains in hospital in a stable condition. He has serious injuries.
We are asking anyone who saw the collision or has dash cam footage of it to contact officers at the Stanway Roads Policing Unit on 101 quoting incident number 140 of 23 September.