Detectives have appealed for witnesses to come forward, including two people who stopped to assist the injured man.
A murder investigation has been launched after the death of a man who was bitten by a dog on a footpath often used by walkers, police said.
West Yorkshire Police said officers received calls from 1.36pm on Saturday reporting an altercation a short time earlier on the old train line footpath off Blacker Lane in the Calder Grove area of Wakefield.
Police said a man was bitten by a dog during the altercation.
Detectives have appealed for witnesses to come forward, including two people who stopped to assist the injured man.
The 55-year-old was taken to hospital in a critical condition and died shortly after 7pm on Saturday.
Police said a 55-year-old man arrested on suspicion of murder and being the owner of a dog dangerously out of control in a public place causing injury remains in custody.
A dog, understood to have been the animal involved in the incident, has been seized by police.
Detective Chief Inspector Michael Cox, of the homicide and major inquiry team, said: “Sadly, a man has died and it is really important that we understand the circumstances of what has taken place.
“We know that two people, one named Sophie, stopped to assist the injured man and direct officers.
“We would urge these two women to come forward to help us with our ongoing inquiries into this tragic incident.
“The initial altercation has happened in an area used by walkers and we are urging anyone who has potentially seen or heard any part of the exchange between these two men to please make contact.”
Anyone with information can contact police on westyorkshire.police.uk/livechat or by calling 101, quoting crime reference 13260465524.
Information can also be passed to independent charity Crimestoppers anonymously via 0800 555 111 or online.
