A man who was shot and dumped at a northern NSW hospital on Saturday afternoon has died, but police said there was "no evidence" his death was related to an Origin-night bikie brawl.

Officers said the man, believed to be aged in his 30s, was dropped outside the Tweed Heads District Hospital at 4:20pm Saturday suffering from a gunshot wound to his torso.

He was treated at the hospital but died later.

A woman was involved in the arrival of the gunshot victim, however police have been unable to locate any family to notify them of the man's death so would not release his identity, confirming he was known to police.

The exterior of Tweed Hospital emergency department, where the man was dumped. ( ABC News: Thomas Mackenzie-Forbes )

"There was a lady involved in the drop off at the hospital yesterday afternoon and she is just one of many witnesses we're interviewing at this stage," Superintendent Wayne Starling, commander of Tweed Heads Police Station said on Sunday.

"She's obviously very traumatised by the incident."

There was no evidence to suggest the attack was motorcycle gang related, police said.

"I'd say that the victim of the shooting was not a member of any outlaw motorcycle gang known to us," Superintendent Starling said.

The Seagulls Club, where two rival bikie gangs allegedly brawled on Wednesday night. ( ABC News: Thomas Mackenzie-Forbes )

Initial media reports linked the man's death to a brawl between rival bikie gangs on Wednesday night, outside Seagulls Club at Tweeds Head, about 4 kilometres from the Queensland border.

"There is no evidence whatsoever to suggest that this fellow died as a result of the brawl at Seagulls last week," Superintendent Starling said.

"There is no bikie problem at the southern end of the Gold Coast or in the local Tweed area … the crime levels in Tweed are the lowest in history."

Investigations involving the local police and the Homicide Squad continue.