Gwent Police are appealing for witnesses after a road traffic collision on East Dock Road, Newport, at around 6.50pm on Thursday 9 November.
Officers were called following a collision between a car and a pedestrian.
The pedestrian, a 40-year-old man, was taken to hospital with serious injuries.
The driver reportedly left the scene following the collision and the car is believed to be a dark coloured Mercedes AMG.
Enquiries are ongoing and police are asking for anyone who witnessed the collision or any motorists with dashcam footage that were using East Dock Road between 6.30pm and 6.50pm to contact them.
You can call them on 101 or send them a direct message on Facebook or Twitter, quoting log reference 2300382748 with any details.
Alternatively, you can call Crimestoppers anonymously on 0800 555 111.