Police have revealed that a man involved in an armed incident in West Auckland on Sunday night was shot several times by police.
Eight armed officers were attemping to apprehend the man, who was being sought in connection with an arson.
Police say that, after an altercation, officers attempted to subdue the man with a taser but for reasons unknown it didn't work.
The man then presented what was thought to be an air rifle and was shot.
Superintendant Bill Searle says the officers armed themselves according to the perceived level of threat.
He says senior investigators have been brought in from outside the district to carry out an inquiry into what happened. The Independent Police Conduct Authority is also investigating.
A 38-year-old man is under police guard in hospital. He is in a serious but stable condition and has been charged with assault.
Routinely arming police 'very dangerous'
Sunday night's incident and the shooting of two officers in Christchurch last week have led to the Police Association repeating calls for officers to have greater access to firearms.
But a taser watchdog group says greater use of the Armed Offenders Squad (AOS) is preferable to routinely arming police, which would be a "very dangerous thing to do".
The group's spokesperson, Auckland lawyer Marie Dyhrberg, says the AOS should be more readily available instead, because "they are people who are fully trained psychologically to understand the situation" and who are very experienced in the use of firearms.
Ms Dyhrberg also wants to know why the taser did not work on Sunday night - was there a technical fault, she asks, or was there something about the targeted man that caused him not to feel the effects of it?
Police satisfied with tasers
Police say however that there are no concerns around the viability or effectiveness of tasers. The man in charge of the taser project, Superintendent John Rivers, says the number of times tasers have failed in New Zealand is comparable with overseas jurisdictions.
During the taser trial there were 16 discharges, two of which were unsuccessful, Supt Rivers says.
Since the national rollout began in March, he says, tasers have been discharged 30 times and on all but four occasions were used successfully.
They don't work at a range of more than six metres, however, and police are considering longer-range ones, such as are used in Australia and Britain.
Prime Minister John Key says he has heard anecdotal evidence of some scenarios where tasers have not worked but he believes that they are generally working pretty well.