A person makes an emergency call for help. Photo: 123rf
Police abandoned 572,037 of the cases reported to them last year - that's almost 60 percent.
In total, it received 962,521 emergency calls and reports in 2023, up from 50 percent from 2019.
The numbers were supplied to RNZ through the Official Information Act.
Of the cases reported to police last year, 179,957 were closed without any investigation at all.
Each case reported to police is assigned a numerical score to determine whether it can be solved in a reasonable amount of time.
If a victim or witness can name a suspect, the case is given 10 points. If they have some evidence of a suspect but don't know who they are, the case is given just 2 points.
Further descriptions of a suspect or their vehicle are worth between 2 and 7 points each, depending on the level of detail.
Those points are added together and if the result is below 7 the case may be closed without any further investigation.
A further 244,312 cases were abandoned after all "reasonable" avenues of enquiry were exhausted, meaning police had done everything they could but had not identified a suspect.
The remaining 147,768 cases were abandoned at police discretion, meaning there were still avenues to pursue but police decided not to.
The number of cases closed at police discretion saw the biggest increase, doubling from 7.5 percent of cases in 2019 to 15 percent of cases in 2023.
During this same period the Police Association repeatedly expressed concerns that the force was under-resourced and struggling to retain staff.
But NZ Police said it could not say whether a lack of resources had impacted the data.
It said its records didn't keep track of which cases had been closed due to a lack of available staff or resources.