Matthew O'Donovan, 22, was found in the early hours of Saturday, July 5, in Ellington. He was taken to hospital and on Thursday, July 10, police were informed he had died.
Enquiries are underway to find out how he came to be lying unconscious on the path and are appealing for the public's help.
Mr O'Donovan, of Eden Terrace, Lynemouth, was found halfway along the mineral line that runs from Lynemouth Road in Ellington towards the coast by two passers-by.
Officers are appealing for information and particularly want to hear from anyone who heard motorbikes in the area between 11pm on Friday, July 4, and 1am on Saturday, July 5.
Northumbria Police Motor Patrols Sergeant Mick Soulsby said: "We're carrying out enquiries to find out how Mathew came to be lying on the mineral line and are keen to hear from anyone who remembers seeing or hearing anything, in particular if anyone heard motorbikes in the area between 11pm on Friday, July 4, and 1am on Saturday, July 5 we want them to get in contact.
"A motorbike was located nearby and one possibility is that he has fallen off a bike, although there may be another reason.
"His family are devastated at his death and we want to be able to give them the answers they need to help them come to terms with such a tragic loss at this difficult time."
A man has been arrested and released on police bail.
Anyone with information should ring Northumbria Police on 101 ext 69191 quoting reference 32 050714 or Crimestoppers anonymously on 0800 555 111.