Gwent Police are appealing for witnesses after a road traffic collision on Cardiff Road, Newport, at around 4.50pm on Thursday 8 February.
Officers attended, along with personnel from the Welsh Ambulance Service.
The collision involved a car and a pedestrian.
The pedestrian, an 84-year-old man from the Newport area, was taken to hospital. He sadly passed away later.
A 44-year-old man from the Newport area had been arrested on suspicion of causing serious injury by dangerous driving, driving a vehicle whilst unfit through drugs, and failing to stop after a road accident.

He is currently in police custody.
A silver-coloured Hyundai i10 car – believed to have been involved in the collision – was located on Gaer Vale a short time after the collision.
Police are asking for anyone with CCTV, dashcam and doorbell footage, or witnesses who may have seen a silver-coloured Hyundai i10 travelling between Cardiff Road and Gaer Vale in Newport around the time of the collision, to contact them.
You can call police on 101 or send them a direct message on Facebook or X, quoting log reference 2400045681, with any details.
Alternatively, you can call Crimestoppers anonymously on 0800 555 111.