A brutal assault in West Auckland where a man was beaten with a piece of wood has been caught in graphic CCTV footage.

Police are appealing for public help to find the men who left a 20-year-old victim unconscious and seriously wounded after an 11pm fight on Tuesday January 23.

Detective Sergeant Chris Goldsmith said the footage captured a fight between four men on Oates Rd, Glen Eden.

"The footage shows a violent, physical altercation between two parties and ends in one victim receiving serious head injuries after he was struck unconscious with a piece of wood," he said.

"This is a particularly vicious and cowardly attack on a male who continues to be struck in the head with a plank of wood, despite lying unconscious on the ground."

The footage is graphic and violent.

"Some people may find this footage hard to watch, but the victim and his family have given their support for police to release the footage with the aim of identifying those involved," said Goldsmith.

"We had to leave out the last part of the footage as it was too graphic to show, however the offender strikes the victim in the face while on the ground in what easily could have resulted in a fatal blow.

A man was beaten with a piece of wood in Glen Eden, now police are hunting the attackers. Image supplied by NZ Police.

"We are determined to find these men and hold them to account over this shocking attack.

"We know this footage is quite grainy, but there are people out there who know who was involved and will recognise these offenders.

"We urge them to do the right thing and contact police."

Goldsmith said the main offender had been described as Polynesian with a large "afro" hairstyle, about 1.82m tall with a large build.

The second offender was described as being Maori or Polynesian, about 1.75m tall, of fit or muscular build and wearing a white T-shirt.

Goldsmith said the two attackers ran off on foot towards Captain Scott Rd immediately after the incident.

"The main victim received serious facial injuries in the attack and is having to undergo facial reconstructive surgery in hospital," said Goldsmith.

"While his associate was also hit in the arms and legs with pieces of wood."

Anyone with information that may be able to assist our enquiries is asked to contact Detective Sergeant Chris Goldsmith on 09 839 0600.

Information can also be provided anonymously by calling Crimestoppers on 0800 555 111.