The Independent Police Conduct Authority says a police officer who held a youth to the ground by using their knee on his head was unjustified in doing so.
On January 12 last year a vehicle appeared to evade an alcohol checkpoint on Fergusson Drive in Wellington by pulling into a driveway.
When police spoke to a youth, they found he had take the car illegally by driving when disqualified.
Police said the driver failed to comply with police instructions, then became abusive and resisted arrest.
During the arrest, it was alleged the officer punched him in the face, threw him to the ground and didn't listen when he said he was having breathing difficulties.
But the Authority found the use of force in taking the youth to the ground was justified.
Video footage showed he was not punched in the face and was "taken to the ground in a reasonably controlled manner given the circumstances", the Authority noted.
However, when the youth was on the ground, the Authority said the officer's use of force to hold him down by placing their knee on the side of his head, even though force applied was found to be minimal, was unjustified.
"The footage shows the youth made no genuine attempt to get up from the ground. Therefore, the placement of the officer’s knee on his head was entirely unnecessary," Authority chairman Judge Colin Doherty said.
The Authority also said the officer should have submitted a Tactical Options Report following the incident.
In response to today's findings, Wellington District Commander Superintendent Corrie Parnell said, "our officers come to work every day to keep the community safe and, in any situation, the use of force is an absolute last resort.
"This officer was faced with a driver who was actively resisting arrest. I am confident they (the two officers present) have learned from this incident and will apply these lessons when making tactical decisions in the future."
The driver was charged with unlawfully taking a motor vehicle and driving while disqualified.