Police were called to Pier Street, Ventnor, on the Isle of Wight, shortly after midnight to reports a 57-year-old man had been assaulted.
Nick Medlin was pronounced dead at the scene. His family said they were "completely devastated".
Two men from the island, aged 31 and 32 have been arrested on suspicion of murder.
A third man, aged 26, was released on bail pending further inquiries.
Mr Medlin, a father-of-two, played bass in a punk band called Manufactured Romance.
In a statement released through police, his family said: "We are completely devastated and totally heartbroken by the tragic death of Nick on Christmas Eve.
"The family wishes to thank everyone for their kind tributes and ask for privacy to grieve at this very sad time."
Hampshire Constabulary has appealed witnesses to come forward.
Det Ch Insp Dave Brown said: "Investigations are continuing today as we work to establish the exact circumstances of this man's death.
"We would like to speak to anyone who was in or in the vicinity of the Rose Inn on Christmas Eve night."
A prison staff blogger, called Know The Danger, posted on Facebook: "Everybody loved Nick Medlin and respected him, and I can say hand on heart he was one of the best officers I have ever worked with in over thirty years. A true professional in every way."
A section of Pier Street was cordoned off for much of Christmas Day but has since reopened.
Family and friends have paid tribute to a prison officer killed on a night out in the early hours of Christmas Day.