An Auckland police officer's tasering of a teenager was "excessive and unjustified", the police watchdog has found.
The 17-year-old was tasered in south Auckland in September, 2016 when he became verbally abusive and resisted efforts to be handcuffed.
In a report released on Tuesday, the Independent Police Conduct Authority found the use of the taser was against police policy as the teen wasn't "assaultive".
"The young man was being restrained by two officers at the time he was tasered. Although he managed to spit in the sergeant's direction twice, the sergeant's use of the taser was excessive and unjustified," IPCA chair Judge Sir David Carruthers said.
The sergeant's arrest of the young man was lawful, but his decision was ill-considered and premature and the arrest "unnecessarily escalated the situation", the IPCA also found.
The teen, who was arguing with his girlfriend on the side the road, was pepper-sprayed while resisting arrest and taken into custody for "behaving in a threatening manner".
In response to the findings, Inspector Julia Lynch said the officer stopped to intervene as the teen was "highly intoxicated".
The man did not make a complaint regarding the incident and it was the police who referred the incident to the IPCA.
An internal employment investigation was still ongoing, she said.
"Lessons have been learnt and we continue to provide training and constructive feedback to help inform decision-making and judgement with our staff."