Police officers have unholstered their Tasers more than 500 times this year and say the sight of the weapon alone is enough to stop most offenders in their tracks.

Tasers were displayed 534 times and fired 82 times in the first seven months of this year, according to police data.

They were displayed 4196 times over the five previous years and fired 623 times - an average of 125 firings each year.

Tasers were first introduced in 2008 and officers were armed incrementally. Use of the weapons peaked in 2013.

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Police manager for capability, Inspector Jason Ross, said the number of people being tasered would have increased as more officers were trained in using the devices.

Tasers were the least injury-causing tactical option used by police, he said. They typically had an injury rate of about 1 per cent compared to about 24 per cent for batons, about 3 per cent for pepper spray and about 89 per cent for dogs.

The presentation of a Taser alone stopped violent behaviour more than 80 per cent of the time, said Ross.

National MP Chester Borrows, who has a history in policing and the law, said Tasers had been very effective.

People had quickly learned it would hurt if they didn't do what a police officer with a Taser told them to do. The weapons had prevented a lot of people from being shot, said Borrows.

"My view is that it's a very good fallback from having to shoot somebody. It's a very sobering thing to... holster a gun and know that you might have to kill somebody and so I think that Tasers certainly serve their purpose."

There had been concerns about how police had deployed Tasers in the past but that was a risk with any weapon and came down to the user, said Borrows.

"If police staff are misusing their powers by misusing Tasers, pepper spray, firearms or anything else, they should feel the full weight of the law upon them," he said.

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Labour spokesman for corrections Kelvin Davis said he liked to think police used the least violent methods to restrain people in the first instance.

A Taser was a better option than a gun, he said.

Davis said he had been tasered when visiting police in America. Part of their Taser certification was experiencing what it felt like to be tasered and he was invited to try it.

"It's the most horrible feeling that you could ever know but then, once it stops, it's over."

The fact that only a small percentage of displays led to the weapons being fired was reassuring, Davis said.

"I think that people, once there's a Taser aimed at them, they comply and those who don't comply end up feeling its bite and, like I say, it's a pretty horrible feeling."

New Zealand First MP Clayton Mitchell, who has a background in self-defence, said carrying Tasers was a far better option than toting firearms.

He thought the use of a Taser was a good thing when the lives of police officers or the public were threatened.

Tasers allowed police to apprehend an offender, then take them to court and let the judicial system deal with them.

He said pepper spray was a good tool in the right circumstances but it could affect bystanders. Some people also had a high tolerance for the spray.

"If you're going to pull out a defence mechanism to use it, you want to be 100 per cent sure it's going to work, because that can actually inflame a situation and again put police lives in jeopardy. That's the last thing we want to have is our frontline police officers' lives being at risk."

The police data doesn't include events where the use of force is associated with fatality, as those events are the subject of internal and external investigations.