An Auckland police officer has resigned after making comments to colleagues about planting evidence in order to use police powers to search cars.
An investigation by the Independent Police Conduct Authority (IPCA) acknowledged an unnamed police officer talked about planting empty "point bags" in motor vehicles to other police staff between June and August last year.
The officer then produced three small zip-lock bags from his vest during the conversation, one of which contained the residue of white powder.
Other officers who were "very concerned" about these comments reported them to their supervisors.
The officer, who worked at Ōtāhuhu Police Station, was stood down immediately but resigned before police could complete an employment investigation. Another officer was stood down at the same time, but was cleared of wrongdoing and has returned to work.
The IPCA, which recently completed its investigation, concluded that while there was no proof the officer actually planted evidence, some officers' comments demonstrated they were "prepared to engage in improper and potentially discriminatory policing practices".
In their investigation, the IPCA identified "shortcomings" in regard to the officer's handling of seized property throughout his career.
In a police statement, Counties Manukau District Commander Superintendent Jill Rogers said the comments made by the officer were "incredibly disappointing".
"Police is a values-based organisation and making those sort of comments was completely unacceptable and totally out of line with our values and the professionalism I expect from my staff," she said.
"The fact that other officers reported this to their supervisors is very reassuring and I think the immediate response by police which saw the two officers stood down while the matter was investigated proves that we do not tolerate this type of behaviour."
IPCA chairman, Judge Colin Doherty, confirmed there was no evidence of wrongdoing, but there was a "level of suspicion over the policing practices of the officer".
In a statement, the IPCA confirmed during interviews some officers said they partly measured success on the job in terms of the number of arrests they made as a result of "suspicious" vehicle stops.
The statement said this gives officers more reason to stop vehicles in the hope of making an arrest, rather than stopping them on reasonable grounds.
It also points to international policing research, showing if officers focus on "suspicious" drivers and vehicles, this is likely to result in discrimination against some groups more than others.
But Commander Superintendent Rogers said officers were trained to know what lawful powers they have to conduct vehicle stops.
"There are countless examples where lawful vehicle stops have removed dangerous drivers from our roads as well as discovering illegal drugs including methamphetamine, firearms, stolen property or wanted persons and prevented further offending and victimisations."
The IPCA recommended in its report that Police clarify its "exhibit and property management" policy, especially in relation to the recording and destruction of evidential items such as point bags.