The use of tasers on children should be eliminated, the National Children's Commissioner has said, after seeing footage obtained by the ABC that shows an unarmed 12-year-old boy tasered by Northern Territory Police.

Key points: Footage shows 12-year-old being tasered by Sergeant Benjamin Watson

Footage shows 12-year-old being tasered by Sergeant Benjamin Watson "I think [tasering a child] should be avoided at all costs," Children's Commissioner says

"I think [tasering a child] should be avoided at all costs," Children's Commissioner says NT Police investigation found the officer didn't break any laws

After watching the footage, National Children's Commissioner Megan Mitchell said she found it difficult to "accept that alternate methods for constraining and apprehending children can't be found and that officers would not be skilled in these".

"I don't think it's ever appropriate [to taser a child] and I think it should be avoided at all costs, unless it's an extreme situation and the public is in extreme danger," Ms Mitchell said.

"These are high-voltage instruments and they pose great risk to developing organs, the brain and eyes, they would hurt and they sometimes even result in death I understand.

"We really should be trying to eliminate the use of tasers and especially in regards to children."

The boy, who cannot be identified, had been a passenger in a stolen car that went for a joyride with three boys in Palmerston in November last year.

At the time, an NT Police statement said: "With such reckless driving in close proximity to schools at drop-off time, we are very fortunate that no children were injured or killed."

The three boys were confronted by police at a Bakewell petrol station and a 17-year-old was wrestled to the ground, a 13-year-old tackled by police and the 12-year-old tasered — an action deemed improper by a judge.

An internal police investigation found the NT officer did not breach any laws, but the Darwin Children's Court on Thursday ruled in the boy's favour when it found the actions of the officer were "improper".

The security footage shows the 12-year-old boy unarmed and barefoot, running from police and chased by plain-clothed officer Sergeant Benjamin Watson with his taser drawn.

Less than three metres away and next to a petrol bowser, the child crumbles to the ground after being tasered in the back.

Officer didn't break law: NT Police investigation

The 12-year-old appeared in court this week to face charges relating to the incident.

He pleaded guilty to unlawful use of a vehicle but was found not guilty of escaping custody and resisting arrest.

Three boys were confronted by police at a Bakewell petrol station. ( Supplied: Facebook )

The court ruled the impropriety of the officer's actions outweighed the low-level nature of the offences.

Sergeant Watson told the court: "I had to use the tools, I had to end this as safely as possible without putting the public at further risk."

The court also heard there were no extraordinary circumstances that warranted the use of a taser on a child or near volatile liquids, as well a car that might have lost control.

Ms Mitchell said the footage should prompt governments to review guidelines they have in place for the use of tasers.

"Especially in relation to children and the damage that can be done to children, and I think that we need to be supporting the police to apprehend young offenders without having to resort to tasers," she said.

NT Police said in a statement their investigation found the officer did not break any laws, but an investigation by the Ombudsman was underway.

"The criminal investigation is completed and no breaches of law were identified," a police spokeswoman said in a statement.

"Yes, the complaint against police is still being investigated on behalf of the ombudsman."

The spokeswoman said the Children's Court finding would have no bearing on any disciplinary action taken against the officer and he is still on duty and authorised to use a taser.