A police officer who used a Taser on a man twice during an arrest used unjustified force, an IPCA investigation has found.
A man was arrested in Christchurch in April last year after he punched the officer, who was at the man's home responding to a call-out.
The Independent Police Conduct Authority found the officer was right to Taser the man in the first instance, as he was being threatening and hostile.
But the authority found the second use of the Taser was not in line with policy, as the man was on the ground in a trance-like state, still suffering the effects of the weapon.
It also found it was unnecessary for the officer, who has served nine years with the police, to put his foot on the man's head during the arrest.
Police said they accepted the authority's findings and had spoken to the officer.