And when the boy was moved schools in 2015 there were further reports about bruising to his face that were never looked into by the authorities.

The boy's father Graham Dillon, 41, killed the boy in February 2016 after years of abuse. He is serving more than three decades in jail for murder.

An inquest into Bradyn's death is examining what the authorities knew when and the adequacy of their responses.

Child and Youth Protection Services started investigating after receiving reports from Bradyn's school about bruises on his face in June 2014.

In the days that followed, the child protection agency knew the school was concerned, that Bradyn had bruises to his face in the shape of finger and hand prints, his attendance was poor, he would sometimes freeze and needed constant reassurance, and that the father had referenced a shady past and referred to court proceedings, the inquest heard.

The agency knew Dillon had a history of family violence against two former partners, including Bradyn's mother, and had heard allegations Dillon would hit the child on the head and kick him in the bottom with a boot when he wasn't expecting.

Dillon had also claimed full custody, that he was engaging with community supports, and that he was going to the Family Court to protect the boy from his abusive mother.

There was a plan to collect information to verify the father's claims, including getting his mental health and drug and alcohol history, police notes and criminal history, the inquest heard. There was a note to correlate the boy's absence from school with his bruises.

But the agency worker who was working on the case, whose name is suppressed, told the ACT Coroner's Court on Thursday that none of that was followed up.

"I don't know the reason why I didn't," she said.

The agency heard Bradyn's bruises were from play fighting with his dad; Dillon said they were from play fighting with his cousins in Sydney.

Bradyn refused to talk about the bruises. He told agency workers "everything was good about dad" but that he sometimes got angry when he was slow and late for school.

Dillon told the workers that when he wanted to discipline the boy he used a "thinking chair" and the occasional smack on the bottom but denied abusing the boy. He said the boy was his world and that he was trying to be a good dad.

The inquest heard Dillon was always talking to the workers about how he was put in foster care and abused as a child, including in front of Bradyn.

Child and Youth Protection Services received another report on August 28 about bruising to the boy's face, and workers went to the school to interview him.

When Dillon found out he was angry and lost control of his behaviour at the school, a senior Child and Youth Protection Services worker said.

She said he was pacing and making phone calls saying he was going to call his lawyer. "Just wait and see what I can do to you," the worker said Dillon told them.

Eventually he allowed the boy to see a specialist child at risk unit at the hospital. The doctor said most of his bruises were explained but one on his ear could not be.

The doctor did not say they were non-accidental.

Child and Youth Protection Services decided there were no proper grounds for an emergency care and protection order and the file was closed.

A senior worker at the agency said at the stage of closing the file they were unsure whether they were dealing with a case of inappropriate chastisement or physical abuse.

She said there were not many options in between closing the file and taking emergency action.

The inquest also heard that Bradyn's mother had called Child and Youth Protection Services in 2013 communicating her concerns about the boy's safety with Dillon.

The inquest continues.