National MP Chester Borrows says the capacity of Counties-Manukau police to solve crimes is being compromised by a lack of experienced detectives.
Mr Borrows, who was a police officer for 24 years, told Parliament on Wednesday that 81 of 103 sworn investigators in the district are not qualified to CIB standards.
He said 43 of them have been in the job for less than a year.
Mr Borrows told Morning Report that means they're not able to deal as effectively with an increase in violent crime in the area.
Counties-Manukau police commander Steve Shortland told the programme the district has always been a training ground for young officers who then take their skills to other parts of the country.