Kiwi-born criminals deported from Australia are contributing to a professionalisation of New Zealand gangs, which is likely to lead to a spike in drug-related violence according to the new Police Association President.
Chris Cahill, who's been in the job since October, says methamphetamine is the biggest driver of crime in 11 of the 12 police districts.
Trade in the drug has turned gangs into a multi-million dollar industry, which is getting worse with the arrival of the deportees from Australia.
"We're getting some key Australian gang figures from big gangs like the Comancheros and Bandidos.
"They're able to add a level of professionalisation to those gangs that we haven't seen before."