Two people were injured - one seriously - and a Yorkshire road was completely blocked when two cars collided yesterday (Wednesday)
The crash happened on the A661 Wetherby Road at Plompton, near Harrogate, shortly before 12.50pm.
Traffic diversions were put in place at the Kestral roundabout and at the Rudding Lane junction. Officers would like to trace a dark-coloured horsebox which was travelling towards Wetherby at the time of the collision.
Police appealed for the driver of a dark-coloured horsebox which was travelling towards Wetherby at the time of the collision to come forward.
They said the driver may not be aware that a collision has taken place, however, they may have information which could help the investigation into the collision.
The horsebox driver and any other witnesses are asked to contact police on 0845 60 60 247.