Sensible Sentencing Trust Tauranga spokesman Ken Evans said it appeared the pre-charge warning system was reducing the load on courts and it was good that offenders were getting an official warning in writing.
However, the police needed to be diligent and make sure offenders were not let off by the system just because police were busy.
He was also concerned the pre-charge warning system was making it appear crime was reducing. The trust was cautious about the system and believed it needed to be watched over by an independent authority, said Mr Evans.
Nationally, 62.1 per cent of offenders ended up before the courts in the year to July 31.
Figures showed 37.1 per cent of offenders were dealt with through non-court action and the remaining cases weren't proceeded with.
Just 12.4 of those committing public order offences and 33.3 per cent of those committing abduction, harassment and related offences were dealt with in court. Figures show 41.9 per cent of those committing theft and related offences ended up before the courts.
A police spokesperson said fewer offenders were now being dealt with through the courts for public disorder, harassment and theft due to the introduction of the pre-charge warning scheme in 2010.
It was one way of reducing the use of court processes for low-level offending, while ensuring crime was still addressed and victims were supported, said police.
They differed from traditional, more informal warnings given in the field, where the offender was not arrested. A pre-charge warning was issued in writing at the police station after a person had been arrested for a qualifying offence.
In order to be given a pre-charge warning, offenders needed to be 17 years or over and to have committed low level or minor offences with a maximum penalty of six months' imprisonment.
Those committing family violence and methamphetamine offences were ineligible for a pre-charge warning, said police.
Police considered a number of factors in dealing with offenders through non-court action including behaviour and attitudes displayed, type of offence, severity of offence, availability of alternative options, wishes of victim, evidential threshold and offender history.
The police figures record unique offenders. Unique offenders are individual offenders counted once in the year regardless of how many times they have been dealt with by police. Offenders are recorded under their most serious offence.