POLICE are investigating a crash on the M4 in which one of the vehicles involved was driven away.

An Audi A3, an Alfa Romeo Brera and an Audi Q7 and another vehicle crashed on the westbound carriageway between Swindon and Chippenham at 7.55pm on Sunday.

As a result of the crash a 79-year-old female passenger, who was travelling in the Audi Q7, sustained back and neck injuries and was taken to Great Western Hospital.

PC Alan King wants to hear from anyone travelling on the M4 at this time who witnessed the collision, or anyone who saw the fourth vehicle involved in the collision before or after the incident.

Anyone with information should call police on 101.