DYFED-Powys Police is appealing for witnesses following a fatal road traffic collision that occurred at approximately 4.30pm on Monday (Jan 7) on the westbound carriageway of the M4 approximately 200-300 yards from Pont Abraham roundabout.
Four vehicles were involved in the collision and several people were taken to hospital.
Sadly, a male passenger, travelling in a white Peugeot Partner van, later died in hospital.
The road was closed and reopened fully at 6.40pm.
Anyone who witnessed the collision or has dashcam footage is asked to contact the Serious Collision Investigation Unit on 101.