Labour MP Clayton Cosgrove says there has been a drop in police numbers for most police districts, including 78 fewer for Auckland and Wellington.
Mr Cosgrove challenged the Police Commissioner, Howard Broad, and the Police Minister, Judith Collins, when they appeared before Parliament's law and order committee on Wednesday.
He asked them about figures supplied by police, showing that by next year all but two police districts will have fewer officers compared to 2009.
He says they show a drop of 32 for the Auckland district, 18 for Waikato, 46 for Wellington and 22 for the Southern district.
Mr Broad replied that while numbers in individual districts may vary, nationwide the total number has increased.