Police are investigating an incident when an officer pushed a teenager off his bike in south Auckland.
The incident was caught on video. Police says they have concerns about what the footage shows.
The clip, posted to Facebook, shows the officer picking 13-year-old Matthew Lamar up and throwing him to the ground, before holding him up against a fence and cuffing him.
Police say they received calls on Saturday evening about a group of youths "acting in a disorderly manner" on Savill Drive and Alderman Place in Mangere.
There was excessive noise, alleged fighting, and cyclists weaving in and out of traffic, causing fears for their safety, police said in a statement.