A 26-year-old man is being treated at Jersey's General Hospital after being hit by a car in the early hours of Sunday morning (15 October).
Police and the Ambulance Service were called to La Rue Du Fort near the junction with Beach Road at around 2.15am.
The pedestrian sustained serious head injuries and was treated by paramedics at the scene before being transferred to the Emergency Department.
A 58-year-old driver has been arrested on suspicion of causing serious injury through careless driving and is in police custody.
The road was closed for four hours so collision investigators could assess the scene. It was reopened at 6:15am.
Officers are requesting any dashcam footage from the area, or for witnesses to come forward.
Anyone who has any information about the collision or who could help with the investigation is asked to call the police on 01534 612612.
Alternatively, people can contact Crimestoppers anonymously using their online form or by calling 0800 555 111.
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