The number of constables on general duties in the Central District's police force has dropped by more than 40 in the past six years.
Police figures released to the Labour Party under the Official Information Act last week show the number of general duties constables in the Central police district, which includes Wanganui, has dropped steadily from 331 in 2009 to 288 this year.
Nationally, there was an almost 18 per cent decline.
The figures are disputed by Police Minister Michael Woodhouse, who last week said frontline and overall police numbers had increased.
Labour's police spokesman Kelvin Davis said the number of constables on the beat had fallen over the past six years in all but one of the country's 12 police districts.