"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.