A man is still on the run after another man was killed in an alleged assault at a campground in northern NSW.

Two men are believed to have become involved in an argument at a campground off Point Lookout Road in Ebor, about 80 kilometres from Armidale.

The altercation between the two men escalated when one seriously assaulted the other, leaving him with serious injuries.

Emergency services arrived on the scene to treat the man, 33, before he was driven to Thora, around 25 kilometres of Bellingen.

Paramedics attempted to treat the man, however he died at the scene.

Police have also been unable to find the other man who was involved in the argument despite establishing a crime scene and beginning an investigation.