Riccardo Holness, aged 42, sustained head injuries during an assault which took place at 1.22am on Sunday, 17 October on High Street, Beckenham.
He was taken to hospital in a critical condition where he died nearly a month later on Friday, 12 November.
A post-mortem examination on Wednesday, 17 November gave the cause of death as blunt force trauma to the head.
A 26-year-old man was arrested on Monday, 18 October on suspicion of GBH and subsequently bailed pending further enquiries.
Detective Inspector Dave Blair, from Specialist Crime, said: “Our thoughts remain with Riccardo’s family who are understandably distraught at what has happened. We are working hard to establish the facts of the incident and would ask anyone who witnessed the assault or who has any information to contact us as soon as possible.”
Information can be provided by calling police on 101 and giving the reference 536/17OCT21.
Alternatively, it can be provided to Crimestoppers, anonymously, on 0800 555 111.