Eight out of 12 police districts are facing a drop in their number of frontline officers.
Police estimates show even districts that have experienced a rise in violent crime, will have fewer police at the end of next year than they did halfway through 2009.
Parliament's Law and Order Select Committee heard on Wednesday that the Wellington district faces a reduction of 46, to 791, over 2.5 years.
Labour says Auckland and Waikato, which last year experienced a rise in violent crime, will also lose officers.
Police Commissioner Howard Broad says some districts were staffed above target levels last year, and that's now being adjusted, but the total number of officers nationwide has increased.