On January 12 police were called to a property on Park Road in Stonehouse with a report that 77-year-old John Coxon had sustained a head injury.
He was taken to Gloucestershire Royal Hospital by ambulance for treatment.
A man was subsequently arrested on suspicion of causing grievous bodily harm in connection with the incident, and was later released under investigation.
Mr Coxon remained in hospital until he died on 25 March.
On Wednesday (August 31) a 64-year-old man was arrested on suspicion of murder in relation to the death of John Coxon.
A 64-year-old man has now been bailed while enquiries continue.
Searches have been taking place at an address in Stonehouse in connection with a murder investigation.
Detectives are still appealing for anyone who has information which could assist the ongoing investigation to come forward.
Anyone with information can provide this to police online by completing the following form and quoting incident 271 of 12 January: You can also call police on 101.