A pensioner arrested on suspicion of manslaughter after a 64-year-old man was killed in a row over a disabled parking space has been released on bail, police said.
The 65-year-old man was held by police following the incident at an Asda supermarket car park in Biggleswade, Bedfordshire, on Saturday.
The victim, from Sandy, was taken to Addenbrookes Hospital in Cambridge, where he died yesterday afternoon, a spokesman for Bedfordshire Police said.
The family of the victim was at his bedside when he died.
Detective Chief Inspector Tim Redfearn, who is leading the investigation, said: "The men were waiting in the disabled parking area at the time and got into a disagreement about parking.
"We know they became involved in a disagreement which resulted in one man punching the other knocking him to the ground.
"It would seem an argument over nothing has led to tragic and devastating consequences for both men and their families.
"I know the supermarket car park would have been very busy on a Saturday afternoon so if you were there at the relevant time please contact the police in confidence."
The suspect left the supermarket following the incident at around 3pm but was arrested at his home address nearby a short time later.
He was released on police bail last night pending further inquiries until August 19, a police spokesman said.
Anyone with information is asked to contact Bedfordshire Police on 101 or the independent charity Crimestoppers, anonymously, on 0800 555 111.