The aunt of the first man shot with a Taser gun says he was holding a weed-eater at the time and police made the right decision to fire when he refused to put it down.

The 18-year-old labourer became the first person to be subdued with a Taser when he was hit with the weapon's 50,000-volt charge in Western Springs on Friday night.

His aunt, who did not want to be identified, said her nephew was fuelled by alcohol and there were a number of adults and children around the Tuarangi Rd flats where police confronted him.

"It was an 18-year-old with alcohol who had gone too far," the woman said.

The man's family said there was an altercation outside the block of flats and he originally armed himself with a hand-saw. He then picked up a weed-eater.

Police told him to put it down more than four times, the aunt said.

"For everybody's sake it was for the best," she told the Herald yesterday.

"I'd rather see him being taken that way than somebody get hurt or he gets hurt or anybody dies."

However, her husband was not so sure about the police decision to Taser his nephew.

The man, who was not home at the time, questioned whether police could have disarmed his nephew by other means, such as using a police dog.

Police would not go into detail about the incident but said the teenager had been charged with assault with a weapon, threatening to kill, possession of an offensive weapon, and possession of a knife.

He appeared in the Auckland District Court on Saturday and was granted bail to reappear today.

An investigation found the use of the Taser was appropriate, said Detective Inspector Bernie Hollewand of the Auckland City police.

The man fell to the ground as soon as the electricity entered his body, via wires attached to him with small metal darts, his aunt said. She visited him on Saturday and said he appeared fine. Police say the Taser is a less lethal option in situations involving violent offenders.

The Western Springs incident was the fourth time police have presented a Taser since the start of a 12-month trial on September 1. In the other three incidents the gun was not activated because people complied with police instructions.

Green MP Keith Locke said police seemed "too eager" to reach for the Taser. He would be asking for details of incidents to check against police guidelines.

Police may use a Taser to:

* Defend themselves or others if they fear physical injury.
* Arrest an offender if they believe on reasonable grounds the person poses a threat of physical injury.
* Prevent a suspect escaping.
* Deter attacking animals.