Police accept that an officer's use of a Taser when a man resisted arrest in Dunedin last year was not just justified.
In a report released today, the Independent Police Conduct Authority (IPCA) found the officer had other options when she Tasered the man on February 13 last year.
The man "appeared to self-harm", before resisting two police officers trying to restrain him and kicking one of them, police said.
Officer C used a Taser after the man challenged and moved towards her.
Southern police district commander Superintendent Paul Basham said Officer C felt threatened but police accepted using a Taser was not the most appropriate option.
"Police officers are put in high-pressure situations every day where they are required to make quick decisions about their own safety, as well as the safety of those around them," he said.
Officer C should also not have been carrying a Taser in the custody area, he said.
"Police strive every day to provide the best possible service and support to our communities but it's important to recognise when we don't get things right.
"Police have now updated Taser policy to make it clear that staff must remove Tasers when entering custodial areas."