Key Points:

Random audits on unauthorised use by police officers of the police central computer system have been successful in terms of catching people out.

Figures released to the Sunday Star-Times show that last year 21 police staff members made unauthorised checks on the system - most of which were picked up in random audits.

The unauthorised acts resulted in disciplinary measures from policy reminders to written warnings and dismissal, the newspaper reported.

In 2007, 36 staff members were reminded of the police code of conduct when it was found they had accessed the central computer system without a proper reason.

Police Deputy Commissioner Lyn Provost said 50 staff members were randomly picked each month to explain their use of the system.

The amount who were found to be misusing it was small as a percentage of the 11,500 police employees, she said.

"What's important is that the public of New Zealand can have confidence that information that is obtained is being used appropriately within the police."

Last year it was revealed that a file on a Tauranga woman at the centre of sexual violation allegations against former policeman Brad Shipton had her file accessed dozens of times by police.

One officer, Steven Hales, resigned after improperly accessing her information.

The woman, Donna Johnson, had laid harassment complaints about him in the past.

The allegations made by Ms Johnson against Shipton were investigated but no charges were laid.