Police say they have heeded the recommendations of a wide-ranging investigation into the deaths of 27 people in police custody over a decade.
The Independent Police Conduct Authority report found eight out of ten of those who died in police custody during the ten-year period from 2000 to 2010 were under the influence of drugs or alcohol.
The most common cause of death was suicide by hanging, of which there were 10 cases. Almost half of those who died were Maori, and all but one were male.
IPCA Chairman, Judge Sir David Carruthers, said deaths in custody were uncommon.
"While it is rare in New Zealand for people to die while in police custody, such deaths can be controversial.