Three men have been arrested on suspicion of attempted murder after a 22-year-old Plymouth man died.
The victim was found unconscious with a "significant" head injury at Kelly Bray, near Callington in Cornwall on Thursday, said police.
He died at Derriford Hospital in Plymouth on Saturday morning.
A 37-year-old man who was arrested is in hospital with multiple and "possibly life-threatening" injuries, said officers.
The others arrested were a 29-year-old man from Gunnislake in Cornwall who has been released on bail, and a 26-year-old man from Callington in Cornwall who remains in custody.
Police are seeking witnesses to the incident at Kelly Bray which happened at about 21:30 GMT.