Police have offered a reward of £10,000 for information leading to a conviction over the murder of a 24-year-old man who was found at a squat.
Billy Henham's body was found in a building in North Street, Brighton, at 16:30 GMT on 2 January.
A post-mortem examination revealed the 24-year-old died following a sustained assault.
Mr Henham, from Henfield, West Sussex, was last seen at 18:00 at a New Year's Eve party held at the site.
His family paid tribute to their son, saying his "guardian angel sadly lost sight of him" the night he was killed.
Five people arrested in connection with his death were released by Sussex Police under investigation.