Police are investigating the sudden death a 27-year-old woman whose body was found on the M4 near Swansea.
Abigail Hussey from Penllergaer was found dead on the carriageway of the M4 between junctions 47 and 48 in the early hours of Tuesday morning.
Emergency services were called but despite medical assistance she was declared dead.
South Wales Police are appealing for witnesses who were travelling in the area.
They are particularly interested in hearing from anyone who was on the motorway at the time and may have seen Abigail or a gold coloured Citroen C4.
Her family members are being supported by a specially trained police officer.