A social worker who sat on a 16-year-old is now working as a whānau support worker at Jean Batten School (file photo).

A social worker who sat on a teen and punched a co-worker in the face is now working at an Auckland primary school.

Uila Esera was charged with conduct unbecoming of a social worker and de-registered over the incidents, which took place while he was working at the Whakatakapokai Care and Protection Residence in 2013.

The residence is a secure facility for young people, run by Oranga Tamariki – then called Child, Youth and Family – in south Auckland's Manurewa.

A decision by the Social Workers Complaints and Disciplinary Tribunal, released this week, said the incidents showed Esera had "a quickness to become angry and a concerning resort to aggression and violence when frustrated".

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﻿He appeared to "lack insight into the gravity of his conduct" and showed a "pattern of violent behaviour", the decision said.

Keren Williams, a residential youth worker at Whakatakapokai, stated the altercation between Esera and the 16-year-old girl began following an argument over ice cream, the decision said.

When the teen yelled at Esera, he went in for a "one man restraint" without any warning, Williams said.

She classed the interaction between Esera and the teen as "the most violent that I've witnessed".

CCTV footage from the incident showed Esera grabbing the girl first by her wrist, then around her neck and chest, the decision said.

She fell to the floor, and he sat on top of her chest to hold her down.

Esera did not dispute using physical force against the girl but said he acted in "self-defence" after the girl punched him out of nowhere, the decision said.

After the incident, Esera was dismissed from his job at Whakatakapokai.

The decision said after being told of the move, he punched his boss in the head and face three times, injuring his neck, chin, nose, forehead and cheek.

Esera was found guilty of common assault at a judge-alone trial in 2015, but was granted a discharge without conviction, the decision said.

The tribunal made the decision to cancel Esera's social worker registration and he was made to pay $5000 towards costs and expenses of the inquiry.

Esera was now employed at Jean Batten School in Māngere East as a whānau support worker.

In a short biography on the school's website, he stated he has a "background in social work, as a police officer and a public servant.

"I also work with the parents and caregivers, exploring and looking at ways and ideas to improve the children's learning and behaviour.

"At times, I will accompany a staff member for a home visit, or support whānau at appointments to outside agencies and on field trips," it reads.

Jean Batten School principal Nardi Leonard confirmed Esera was an employee.

However, he had been placed on leave "while the matter is worked through", she said.

"We're working with the Ministry of Education and New Zealand School Trustees Association to ensure we handle this matter in line with best practice."

Ministry of Education spokeswoman Katrina Casey confirmed the ministry was working with the school.

"We . . . are aware the Board is working through a confidential employment matter and has taken advice from New Zealand School Trustees Association."

Leonard said she could not comment any further on whether Esera had contact with children at the school.