Derbyshire Police have re-issued an appeal as part of their investigation into the death of Christopher Henchliffe.
Detective Inspector Greg McGill, who is leading the investigation, has again asked for witnesses to the incident to come forward with whatever information they might have about the alleged assault.
On Sunday 3rd July officers were called by staff to Chesterfield Royal Hospital to reports of a man being treated for serious head injuries.
Early investigations suggested that Mr Henchliffe had been assaulted on Corporation Street, outside the Pomegranate Theatre, sometime between 4am and 4.30am on that day.
Detective Inspector Greg McGill said: “We know from CCTV images that there were a lot of people in the area of the alleged assault. Many of them have already spoken to us but we know there are others who have not yet come forward.”
“I’m appealing directly to those people to ring me or my team on 101.”
Mr Henchliffe was later transferred to the Royal Hallamshire Hospital in Sheffield where he died on Tuesday 12th July.
21-year old Benjamin Edwards, of Fieldview Place in Chesterfield has been charged with causing grievous bodily harm to Mr Henchliffe.
Two other men, both 24-years old, were arrested on suspicion of causing grievous bodily harm and have been released on bail while the inquiry continues.
Anyone who may have seen what is alleged to have happened or has information that might help Police with their investigation is being urged to contact them on 101, quoting reference number 16000177569.