Officers were called to Stocks Lane about 11am on Sunday, 18 October following a crash involving a car and a cyclist. The car failed to stop at the scene.
The vehicle is described as a black estate with a dog crate in the rear. The driver is described as a man in his 50s and a woman with long dark hair was in the front passenger seat holding a dog.
The front wing mirror of the vehicle was knocked off as a result of the collision.
The cyclist – a 54-year-old from Chichester – suffered serious injuries requiring hospital treatment, including a fractured collarbone, a broken arm and a punctured lung.
Nick Stevens of the Collisions Unit in West Sussex said: “We are appealing to members of the public who may know the identity of the driver involved in this crash and ask that they come forward and assist with enquiries.
“Anyone who witnessed what happened or who has dash-cam footage of either party prior to the incident is asked to report online or call 101, quoting 423 of 18/10.”
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