Police say an assault on a teenage boy that was filmed and posted on YouTube was planned to give the perpetrators "street cred".
They say the assault, which lasted about 10 minutes and was watched by up to 30 teens - some filming on cellphones - appeared to be a copycat of similar crimes overseas.
Police were not aware of the March 30 Hastings assault until a tip-off about the YouTube video late last week.
Two boys aged 14 and 16 have been charged with assault and are due to appear in the Hastings Youth Court tomorrow.
Police are deciding what action to take against a third boy, aged 15, who allegedly filmed the victim being punched, kicked and humiliated, and then uploaded the footage on to the popular video website.
Police have also seized a video camera, computer, and cellphones, the cellphones featuring downloads of similar assaults from YouTube and other sites.
The assault may also have been posted on Bebo, a popular networking website, and police have not ruled out the possibility that the youths involved organised and filmed other assaults to post on the internet.
Police contacted YouTube when they became aware of the video, but the website operators had already removed it.
Sergeant Dave Greig, youth services co-ordinator at Hastings police, said the film was posted about five days after the assault and remained there for about a week.
Mr Greig said its intent was sinister. "It's been put on the website with the intention of humiliating the victim. That humiliation has been keenly felt."
He said the film's makers had also wanted to gain "notoriety, fame or street cred", planning the incident to put it on YouTube.
The images found on the cellphones also suggested the assault was mimicking similar videos posted in Australia and Britain.
The 16-year-old victim had not contacted police for fear of retaliation, despite suffering a cut to his mouth, and bruising to his head, shoulders and back.
He and his parents did not want to speak publicly. Mr Greig would not reveal details of the assault while it was before the courts, including who had informed police, and if and how the victim was lured to the place where it happened.
He did, however, reveal that a large group of young men and women watched the assault.
"Twenty to 30 youths are visible on the camera," he said. "It's apparent from the video that during the course of the incident a number of youths have been recording what was taking place on camera phones."
He said none of them tried to disguise their identities - "Everyone's in plain sight" - and more than the two arrested had kicked and punched the victim.
"They were also others inciting and encouraging what was taking place. At the conclusion of the assault, he [the victim] was subjected to some humiliating and degrading behaviour."
Mr Greig would not reveal what that was, except to say it was not sexual.
The assault took place in a park and the youths had come from at least two schools, he said.
Further arrests were likely and police were seeking advice on whether any footage found on Bebo could be classed as "objectionable material" and therefore illegal.
They also planned to talk to all Hastings high schools about the incident once holidays ended.
Last month, YouTube was banned from public schools in Victoria, Australia after the posting of a recorded assault on a 17-year-old girl by a gang of male school students on the outskirts of Melbourne.
Internet safety watchdog Netsafe said it was aware of similar incidents in New Zealand.
"Any kind of bullying which re-victimises the victim again and again ... is of concern to us ," spokeswoman Rachel Harrison said.