Police allege an officer was subjected to a "prolonged" assault in Auckland on Thursday.
Auckland City District Commander superintendent Karyn Malthus says it's concerning the incident occurred in front of "a number of bystanders - including those who filmed then shared it on social media".
The incident began when police received reports of a man assaulting a woman in a vehicle on Quay Street about 9.20am.
"While this was being reported to police, the vehicle drove off along Tāmaki Drive towards Mission Bay," Malthus said.
"Police responded to this report and the vehicle was eventually located on Kitemoana Street, Ōrakei.
"It was established that the registered owner of the vehicle had numerous warrants for his arrest on serious matters.
"The driver attempted to evade police before he stopped the vehicle near the intersection with Tāmaki Drive."
Police said it was when an arrest began that the man allegedly began to assault the officer.
Malthus said the man was eventually tasered and arrested by other police that arrived.
"As a result of this incident, the officer suffered a facial injury, as well as grazes and was taken to Auckland Hospital for observation.
"Our staff go to work every day to keep our community safe, and this video shows a police officer in a very dangerous, and vulnerable situation.
"It is incredibly fortunate that the outcome was not worse and we are currently providing our officer with support."
The 41-year-old man involved is facing a number of charges including resisting police, injuring with intent to injure, possession for supply of methamphetamine and escaping police custody.
He is due to appear in the Auckland District Court on Friday.