A driver died when his car left the road and hit a wall in Surrey.
Surrey Police said the man, who was in his 20s and driving a Vauxhall Astra, suffered fatal injuries during the crash in Ray Lane, Lingfield, on Tuesday.
Officers want to trace the driver of a white refrigerated van who stopped at the scene and spoke to another witness.
He was said to be "possibly Asian", spoke broken English, and was aged about 25 years old.
The force said the road was closed for about five hours following the incident at about 0140 BST.