Detectives are trying to discover what happened to a man found with serious head injuries in a Dorset lane.
The man, who has not been named by police, was found in Dudmoor Farm Road, Christchurch, earlier on Monday.
Dorset Police said he was in a critical condition at Southampton Hospital's neurological unit.
Officers are investigating whether the man was struck by a vehicle. The road was closed for a time to allow experts to examine the scene.
Anyone who was in Dudmoor Farm Road or Marsh Lane at about 12:00 BST is urged to contact police.