Wiltshire Police are renewing their appeal for witnesses to an accicent which closed the M4 for several hours on Friday.

Police were called at 4.05pm to reports of a collision involving one vehicle on the westbound carriageway near to junction 17 for Chippenham.

PC Steve Hutton, of the Roads Policing Unit, said: "At approximately 4.05pm on Friday 13th March 2015, a beige Citroen C4 was travelling in lane three, westbound, on the M4 between junction 16 and junction 17.

"For reasons as yet unknown, it appears the driver has lost control, veering from lane three to the hard shoulder, before colliding with a barrier, coming to rest in lanes two and three.

"The M4 was closed for four hours while a police investigation was carried out."

The driver, a 71-year-old man from South Wales, suffered minor injuries and was taken to Southmead Hospital in Bristol, by land ambulance.

The front seat passenger, a 69-year-old woman also from South Wales, suffered a fractured sternum and leg injuries. She was taken to Southmead Hospital by Wiltshire Air Ambulance.

Both are believed to be making progress.

Any witnesses to the incident who have not yet spoken to police, should call PC Hutton of the Roads Policing Unit on 101.

Alternatively, call Crimestoppers on 0800 555 111 where information can be left anonymously.