Police investigating a fatal road accident want to hear from a motorist who was on the road at the same time.
The crash happened at 1520 BST on Saturday on the A65 Settle to Clapham Road, near Long Preston.
A man and woman, who were on a motorbike, were killed in the accident.
Police are trying to trace the driver of a black MG Rover saloon which was on the A65 at the time.
It is thought he could have been the last person to see the motorcycle which may have overtaken him.
The driver is described as being in his late 40s, and was wearing a green jumper.