An investigation is underway after a man was assaulted and knocked unconscious by an alleged Mongrel Mob gang member in Christchurch early on Sunday.
Kyra Amira-Ria, who witnessed the attack on Oxford Tce in the CBD, told Stuff it was "horrific and disgusting".
"Definitely hard to witness something so gutless," she told the publication.
Police confirmed the victim was taken to the hospital where he remained on Monday night.
Det Snr Sgt Nicola Reeves said the victim was punched by the alleged gang member, causing him to fall to the ground and hit his head on the pavement.
The alleged offender was part of a group of Mongrel Mob members socialising in the city at the time, Reeves said.
She said the alleged attacker is described as Māori with tattoos on his arms, wearing black clothing, a black hat, and a red bandanna wrapped around his wrist.
"Given the large numbers of people who were in the area at the time, police believe members of the public may have videos or photographs of the assault and/or the offender.
"Anyone who has information about the assault is encouraged to contact police on 105 quoting file number 210131/5776 or anonymously on 0800 Crimestoppers."
The incident came after reports gang members were coming to Christchurch at the weekend for a national meeting.