An influx of vetting applications has swamped police resources and put pressure on the Defence Force.
Official Information Act documents from the military, released to RNZ, show a delay in police vetting checks.
These checks are done during the job application process.
The document says the backlog is because of the implementation of the Vulnerable Children Act, which stipulates that anyone in central and local government must be vetted if they are working with children or vulnerable people.
As well, last year's mosque terror attacks in Christchurch also resulted in more people requiring police vetting.
The document says under an agreement with police, the usual processing time is within 20 working days, however last year it continued to rise and peaked at 38 days.
"In August, the average time dropped to 27.5 days and through to mid-October has been continuing to show further improvement."
As a result, the Defence Force has introduced several measures.
It has refined its internal processes, as well as monitoring processing times.
The police have also been given some additional funding on a year-long trial basis from the SIS to try speed up the processing.
A police spokesperson said: "Police have recruited additional resources with the assistance of additional funding from NZSIS, which has contributed to a significant time reduction in the release of police vetting results.
"Additionally, we are always reviewing and working to improve our systems and processes. We currently have continuous improvement work underway with a goal of further streamlining our vetting processes. It should be noted that a small number of vetting requests are complex and can take some time to process.
"We presently have 74 requests from the New Zealand Defence Force in our system (as at 2.30pm, 21 February)."
- 15 are awaiting processing, the oldest being 2 working days
- 55 awaiting QA, the oldest being 16 working days
- 4 under review, oldest being 29 working days - in cases like these the relevant agency will be informed of the delay