Wiltshire Police are appealing for a key witness to come forward after a Ford Ka and Vauxhall Insignia collided on the A361 between Swindon and Highworth.

The incident happened at the Vickers roundabout next to the South Marston Industrial Estate at around 5.30pm on Tuesday, September 8 involving a blue KA and black Insignia.

PC Steve Yeates said: "We would like to speak to a woman who stopped after the collision to check to see if one of the drivers was OK. Unfortunately she left before the driver could get her details.

"We know she was driving a red saloon/hatchback, possibly an Audi A3/A4, and was travelling north bound along the A361.

"We believe she is a key witness and would urge her to come forward as soon as possible.

"Also if anyone else saw this collision or has any information relating to it please can they call me on 101 or anonymously via Crimestoppers on 0800 555 111."