People experiencing mental illness will suffer more from the introduction of Taser stun guns into frontline policing, says the Mental Health Foundation.
It says the Taser was fired in 50 per cent of cases involving mental health emergencies, but only 11 per cent of criminal cases in its year-long trial, according to an analysis by the New Zealand College of Mental Health Nurses.
Mental Health Foundation chief executive Judi Clements said the vast majority of people with mental illness were no more likely than anyone else to commit a violent crime.
"In fact, as these figures indicate, they are more likely to be victims of violence," she said.
Thirty-two Tasers will be fitted with cameras before being initially introduced to three police districts in Wellington and Auckland.
The recommendation went to Parliament on Wednesday but Police Commissioner Howard Broad said nothing new emerged from the debate to suggest the decision should be further delayed.
But the foundation, with the New Zealand College of Mental Health Nurses and the Royal Australian and New Zealand College of Psychiatrists, urged wide consultation with the mental health sector before the introduction of the stun guns.
"The risks posed to people taking prescribed medication for mental illness are unknown, as are the long-term effects of Taser use," Ms Clements said.
Taser safety tests conducted in New Zealand were performed in highly controlled environments with healthy volunteers and bore no resemblance to the real-world situations, she said.
In the year 2006-07, police responded to more than 8000 callouts to mental health incidents in the community.
Ms Clements said the Mental Health Foundation believed the responsibility for mental health crises should be shared between police and mental health services.
"The use of Tasers in mental health emergencies needs to be fully investigated before this weapon is sanctioned for use on the general public."