The warnings are most commonly used to resolve public order offences, with disorder and breach of liquor ban offences accounting for half of all of those issued.
They can be issued only to offenders who are aged 17 years or older and have admitted committing a low-level offence with a maximum penalty of six months' imprisonment or less, but exclude methamphetamine and family violence offences.
Mr Perry said the warnings were counted in official police statistics.
For the 2011/12 financial year warnings resolved 21,811 charges, and reduced new charges to the District Court by 12 per cent.
Police estimate the warnings saved just under 37,000 hours of frontline officer time.
Examples
* A 35-year-old man was given a pre-charge warning by Queenstown police after he allegedly pulled a bush from its planter box outside Eichardt's Bar. The man later replanted the bush under police supervision.
* A 73-year-old pensioner received a warning after being caught shoplifting in Dunedin in March. The woman was nabbed by security staff stealing hair straighteners from Farmers, and was issued with a warning.
* Five teenagers were arrested in Queenstown after a witness saw them driving with a turkey in a box on the back of their ute. They were released with a pre-charge warning. The bird was released unharmed.
* A 21-year old man who attempted to tackle former All Black lock Tom Donnelly after a match at Carisbrook in August was released with a warning.
