A refusal by the police to release any details of their response to wrongly coded burglaries in South Auckland is being called a "snow-job".

A police investigation found that about 500 burglaries were wrongly reclassified as other offences or incidents between 2009 and 2012 in Counties Manukau.

Police and the acting Police Minister Judith Collins have said it was an isolated incident, and spot audits nationwide have been put in place to ensure the integrity of crime statistics.

There was no information to suggest it had happened elsewhere, police said.


But police have refused to reveal any details of the spot audits, and District Commander Superintendent John Tims could not answer when they started, or whether they had uncovered any irregularities.

A police spokesman said the data was complex and it would take considerable time to collate.

Labour police spokeswoman Jacinda Ardern said the responses suggested nothing had changed.

"How can police give an assurance to the Police Minister on Saturday, when they can't give an assurance that there were no irregularities? That seems extraordinary to me." New Zealand First leader Winston Peters called the police response a "snow-job".

"It's not credible. If they can't tell you the details, then there's totally nothing going on."

Police have said the officers involved had not understood the rules and that Commissioner Mike Bush, who was in charge of the Counties Manukau district over the period in question, did not have responsibility for crime statistics.

A police spokesman said: "Since 2012, there has been only one investigation into incorrect recoding of crime information, and that was in the south area of Counties Manukau. Had the same issue been detected anywhere else, it would have been appropriately investigated and dealt with."