Police have released images of five men who may have seen a fatal fight in Kings Cross before Christmas, after no witnesses came forward.
Police said they have no witnesses to help with their investigation into the death of Calum Grant, who suffered severe head injuries during the fight in the early hours of December 23.
Officers were called to Darlinghurst Road about 4.40am and found the injured 46-year-old.
He was taken to St Vincent's Hospital but died the next day.
Police formed Strike Force Kearn to investigate his death and arrested a 42-year-old man in Redfern on the morning of Christmas Eve.
He was questioned, but later released without charge.
Detective Sergeant Gavin Bradbury, from Kings Cross police, said the area was crowded with revellers but no one had come forward.
"This is now a homicide investigation and, in order for it to go forward, we really need to speak with anyone who might have seen anything at the time of the incident," Detective Sergeant Bradbury said in a statement.
"Your information could be the difference between this case being solved or not."
Today police released CCTV footage of five men who may have witnessed the fight and asked for them to come forward.
Anyone with information is urged to phone Crime Stoppers on 1800 333 000.
Information would be treated confidentially, police said.