Police are dealing with burglars as young as nine, with some young law-breakers hardened criminals by their early teens.

Official crime and apprehension statistics for youth appear to show a decline in numbers, but those on the frontline say offenders are getting much younger and their debut crimes are more serious than ever.

"Once upon a time we would see kids, they would start off with shoplifting. What we are seeing now is the first time somebody comes to our attention, maybe when they're committing an aggravated robbery, or are involved in a fleeing-driver incident or burglaries, often that is the first time they come to our attention," says Manukau District prevention officer, Inspector Dave Glossop.

"It's quite typical to be dealing with a 15-year-old for a serious crime".

But frontline officers believe that increasingly offenders are even younger still.

The Manukau Police District has recently been dealing with nine-year-old burglars, and Insp Glossop says it's not uncommon for 11- and 12-year-olds to be driving stolen cars.

Three teenagers, aged between 15 and 16, died after the stolen cars they were in crashed in incidents in south Auckland and Masterton.

Invercargill police last week this week revealed they're looking for an 11-year-old burglar who's on a crime spree.

Police apprehension figures compiled for Newshub by Statistics NZ show in the 2014 calendar year (the most recent data available) there were more than 5400 offences involving children aged 13 or younger.

More than 430 of those were committed by children aged nine or younger.

An "apprehension" refers to police dealing with the offender in some way, including by giving an official warning or organising a family group conference.

The police are also up against what Insp Glossop describes as a "perverted" version of Faginism. That's a tag stolen from the Charles Dickens character who ran gangs of criminal underlings. However, Insp Glossop says in today's version Fagin would be someone in their mid-teens.

"A case recently was a 15- or 16-year-old getting a nine-year-old to do the break-in by climbing in the cat door kind of scenario" he says.

The 28-year veteran says it's disappointing rather than shocking, and he points out the majority of offenders are good kids who respond to intervention.

"There is simply that small hardcore group that don't care."

Newshub.