Kaitaia Police are seeking the public's assistance in an ongoing investigation into a serious assault on Friday morning.
Police were called after two members of the public were assaulted outside the PAK'nSAVE in Kaitaia on 17 November.
Detective Sergeant Russell Richards says the initial incident unfolded inside the supermarket before 11am.
"Two men, one of whom was wearing a gang patch, were arguing in one the aisles.
"Team members intervened and both parties moved on. However, a short time later an associate of the man wearing the patch has arrived at the supermarket.
"It's at this point that the associate has approached two members of the public not connected to the initial incident and began to assault one of them."
The male victim was knocked unconscious.
Detective Sergeant Richards says thanks to brave intervention from supermarket team members and members of the public, the assault was brought to a stop.
"If it's not for this action, the offender's cowardly act could have resulted in a far worse outcome.
"Police and ambulance staff were called to the scene, with the victim transported to hospital. He is understandably shaken, and is recovering."
The offender had left the area, but Police are following good lines of enquiry.
"Police have examined CCTV footage of everything that has taken place," Detective Sergeant Richards says.
"This is an appalling display of violence and it has no place in our community.
"Police are committed to holding those responsible to account for their actions, and I'm calling on anyone who has not yet spoken with Police to assist our investigation."
Anyone with information to assist the investigation is asked to contact Police on 105 quoting the file number 231120/9056.
Information can also be provided anonymously through Crime Stoppers by calling 0800 555 111.
