The Police Association admits new police crash statistics are high but says officers have to report any damage -- including minor dents from reversing out in carpark buildings.
Official documents obtained by Radio New Zealand revealed police were involved in 810 crashes in the year to June.
Police staff were to blame for 500 out of just over 800 police car crashes in the past year.
Of the crashes in that period, 44 officers crashed more than once, three crashed three times and two staff members crashed four times, Radio New Zealand reported.
Police Association vice president Luke Shadbolt said minor damage to police vehicles had to be reported and this was included in the figures.
"We have an obligation to report all incidents of police cars, including dents from backing out in a police carpark building," he said.
Mr Shadbolt also said with the help of mobility devices, police now spent more time on the roads, rather than at the station.
"Mobility devices mean police spend more time on roads and this could increase the risk of minor crashes," he said.
He said on average, police staff travelled up to 90 million kilometres per year with about 3100 vehicles on roads.
"It's quite a significant amount of time on roads."
Mr Shadbolt said offenders were also to blame for the spike in number of police cars.
"It's not unusual for offending drivers to try and ram and damage police cars.
"Often it can result in multiple police cars being damaged," he said.
He said crashes also occurred when responding to different incidents in a "prompt and timely manner".
"It's not an uncommon phenomenon and happens relatively frequently," he said.
Mr Shadbolt admitted crash figures were high but injury rates were "relatively low".
"Accidents are occurring at low speeds and it's more than likely causing minor damage to the vehicle," he said.
He said there was an ongoing driving course police had to complete and they needed to be certified to take part in high speed driving.
He said most of the frontline staff had "gold standard" in driving, which meant they had a driving review every year.
A police spokeswoman said officers "drive to a very high standard in often difficult and stressful situations".
However, all crashes involving staff in police cars were investigated and, if staff were found to be at fault, they were held to account like any other driver.