UPDATED 8.53am: A 21-year-old man brutally bashed after attending a birthday party in Naenae has died overnight.

Jardin Daniel Whanga-Elliott was chased by a group  down a street and  assaulted in the early hours of Sunday.

He was found unconscious about 3.30am near Seddon Street and  rushed to Wellington Hospital with severe head injuries.

Earlier reports suggested he was unlikely to survive his injuries. 

Police believe about 30 people were at the 21st and are appealing for witnesses to the attack or those that attended the party to come forward.

Talosage Terry David Moreli has been remanded in custody after appearing in the Hutt Valley District Court charged with assaulting the man and a separate charge of assaulting another man.

Police were now treating the death as a homicide inquiry and were working to piece together what happened.