Thirty police officers across the country have been convicted or accused of serious charges within the past year, including one who filmed a teenager in a shower.

Photo: RNZ / Diego Opatowski

Figures released under the Official Information Act have also revealed five non-sworn police staff have faced charges, including one who is due to be tried in Auckland on sex charges later this month.

Twenty-two police officers are still being dealt with through the court system, facing charges largely relating to assault against women and children.

Nineteen charges laid against 17 officers relate to offending which happened while on duty.

Police National Headquarters said the districts which those officers were associated with cannot be given out for privacy reasons.

Radio New Zealand understands at least nine of them are from the Auckland district.

New Zealand First's police spokesperson Ron Mark said about 0.3 percent of the New Zealand police force was represented in these figures.

He said he thought the police followed thorough processes when investigating their own.

"I think police command understand if they have officers who are transgressing, that needs and must be dealt with to keep the integrity of the police force."

He said it was important to note the very high stress involved in being a police officer.

Mr Mark said common issues among officers included Prolonged Duress Stress Disorder (PDSD), marriage break-ups and mental health issues.

"We have to keep all those things in mind but sometimes police officers need to accept they are going to be scrutinised a hell of a lot more, and that is right and proper."

Labour's police spokesperson Kelvin Davis said the police should be more open about allegations faced by their staff.

"It highlights the whole problem around violence, domestic violence and sexual violence that people refuse to talk about it and hide the issue... sweep it under the mat and hope it goes away.

"And that's the wrong attitude to take, in particular by the police. They need to be open and up front in particular about what's going on."

Mr Davis said while people, including police officers, deserved the right to privacy, the police needed to be more transparent.

"They shouldn't be hiding which district these police are working in, because there are so many policemen that no one could be identified.

"So I think that that excuse is a bit lame. And like I say, they just need to be the ones that set the example and talk about this issue," said Mr Davis.

"If it's a problem in the police force, then say it's a problem in the police force because then that will give other organisations the courage to speak about it being a problem in their workforces as well."

Criminologist Greg Newbold said the police were facing far more accountability than ever before.

"If no one in the police was getting prosecuted then I would be worried.

"But the fact that you are getting police prosecuted gives me confidence that the system is working and they're being held to account."

Mr Newbold said when the police did make mistakes, they should confess to it publicly and not wait for media to ask for the information under the Official Information Act.