The M4 has reopened in Wiltshire after a serious crash but National Highways is warning drivers to expect delays.

The westbound carriageway of the motorway was closed between junction 15 at Swindon and junction 14 at Hungerford for over 12 hours after an incident involving a car and a lorry.

Police say a serious injury was sustained in the crash, which took place in the early hours of the morning on Friday, October 4.

Shortly before 2pm, National Highways confirmed lanes ones and two heading westbound had reopened.

READ MORE: Serious crash shuts M4 outside Swindon overnight

However, lane three remains closed at the time of writing while final clean up works are carried out.

National Highways warned that there are delays on the route with about a mile of congestion needing to clear before traffic returns to normal levels.

The M4 was initially closed in both directions while an air ambulance attended the scene.

While the eastbound carriageway reopened after several hours, the westbound carriageway remained shut throughout the morning rush hour to allow Thames Valley Police to carry out collision investigation works.

A spokesperson for the force added: “This is due to a serious injury collision.

“We aim to have to carriageway reopened by mid-morning.

“Thank you for your patience.”