"They told me to f-off the road, and f-off home... I kind of swore to myself, for them not to hear, I whispered for them to leave me alone, and then all of a sudden I saw him get out of the car, and that's when it happened.
"A cop came out of the car and came from behind and pulled me off my bike, then slammed me on the ground. Then he picked me up and ... threw me against the fence.
"[It was] pretty shocking from a police[man] - I would expect it from someone off the streets, but not from my own police. It was uncalled for, unnecessary."
Matthew's mother, Rangi Heather told Fairfax the officers overreacted. She admitted her son gets "lippy" sometimes, but is generally a good kid. She wants an apology from police.
"I don't think it's appropriate for the police to be hitting our children... totally inappropriate, I would say abusive.
"I'm just trying to understand why did he react like that? I just want to get to the bottom of why he was a bit more aggressive than what he should have been."
The Facebook clip shows a group of teenagers walking along the footpath in Mangere with a couple of the group on bikes with large speakers when a marked police car pulls over.
Two officers get out of the car, approach one of the teens on the bikes and one officer pushes him off, knocking the bike to the ground.
The uniformed officer then pushes the teen up against a chain-mail fence while his friends ask whether the one holding the phone is recording.
Counties Manukau west area commander Inspector Jason Hewett said police received multiple calls around 5pm on Saturday about a group of youths acting in a disorderly manner on Savill Drive and Alderman Place in Mangere.
The reports were of excessive noise, alleged fighting and cyclists weaving in and out of traffic which caused fear for their safety.
"Police have concerns around what can be seen in the video posted on Facebook and accordingly have begun a full investigation into the incident," Hewett said.
"We appreciate the high level of interest however we cannot comment any further until the investigation is complete."
Posted on Saturday night, the two and a half minute video has already been viewed more than 37,000 times, been shared by 625 people and more than 1000 people have liked it.
One of the teens in the group, Matthew Lamar, wrote on the post that a woman said she would ring the police so they ran down the street and hid.
A cop who caught up to him told him to "hurry home" so he started biking away.
Matthew said the police officer came back as they were going home in a group and again said to go home.
The teen said he swore at the cop under his breath which was when he got out of the police car and "threw me down off the bike then picked me up and threw me against the fence and cuffed me".
During the video, one of teens says: "It's recording, it's recording."
Another says: "What the heck, gee? Aww gee, that's sad. He didn't do anything."
