Detectives have re-appealed for witnesses after the tragic death of Chris Henchliffe.
Detective Inspector Greg McGill, who is overseeing the investigation, said: "From CCTV images we know 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."
Staff at Chesterfield Royal Hospital called police on Sunday, July 3, to tell officers that 26-year-old dad Mr Henchliffe had been brought to A&E by ambulance.
According to police, he was allegedly attacked by three men outside the Pomegranate Theatre in Corporation Street sometime between 4am and 4.30am that day.
Mr Henchliffe, of Maynard Road, Chesterfield, was later transferred to the Royal Hallamshire Hospital in Sheffield with serious head injuries.
He sadly died on Tuesday morning.
Benjamin Edwards, 21, from Fieldview Place, Chesterfield, was subsequently charged with causing grievous bodily harm.
In light of Mr Henchliffe’s death, police are consulting with the Crown Prosecution Service about the charge.
Mr Edwards is next due to appear at Derby Crown Court on August 2.
Two 24-year-old men, arrested on suspicion of causing grievous bodily harm, have been released on bail while enquiries continue.