The opening day of the inquest into Luke's death heard that around April 2013 - about 10 months before the youngster was killed by his father - Greg Anderson held up a knife while in the car with his son and said: "This could be the one to end it all."

But police and Department of Human Services social workers later ruled they were not satisfied Luke was in danger because the boy said during an interview with authorities that he loved his father and was not in fear of him, the Coroners Court heard on Monday.

Luke was killed by his father on February 12 when attacked with a cricket bat and a knife at cricket training in Tyabb. Mr Anderson, 54, was later shot by police and died in hospital.

The inquest also heard Luke's mother, Rosie Batty, contemplated calling police when she saw Mr Anderson at training that day, knowing his presence was breaching an intervention order.

But Ms Batty told the court she decided against doing so because she did not want to embarrass her son, she had been traumatised by previous attempts to have police arrest Mr Anderson at the oval, and she had given police his address a week earlier.

"I thought you know what, they have got his address, it will be better if they arrest him discreetly and not in front of Luke in a public place," she said.

There were four warrants for Mr Anderson's arrest at the time he attacked Luke, including child pornography charges that were laid in January 2013. He also had intervention orders against him, one preventing him from having any contact with Luke outside cricket and football matches at weekends, and another taken out by a housemate about a month before Luke was killed.

With a large framed photograph of her son in front of her, Ms Batty tearfully told the court of the stress, frustration and fear she experienced in trying to ensure Luke's safety from his father, a man she was "terrified" of and feared saying no to.

"He was everything to me. He was my only son, my only child," Ms Batty said of Luke.

"He was the centre of my life. I made every decision for him.

"It was an ongoing journey that I was trying to navigate through and even now I think I am still doing that. But I can't get my son back.

"When this is all over I can never get my little boy back ... I never want anyone to be sitting here where I'm sitting."

Rachel Ellyard, the counsel assisting state coroner Ian Gray, said Luke told his mother about what his father had said in the car with the knife.

Ms Batty later said Luke had "clammed up" when she tried to get more information.

He later inferred she had made up the claim, she said, when she raised the incident during Luke's interview with a police officer and social worker.

Ms Batty told the court she wanted Luke to have a relationship with his father despite his history of violence towards her and his mental-health problems, and never feared he would harm Luke.

But soon after the incident in the car, the court heard, she realised Mr Anderson could not be alone with Luke and so an intervention order was put in place.

A recording of a court hearing from April 2013 was played to court. In it, Ms Batty outlined her fears of Mr Anderson and magistrate Jennifer Goldsbrough said she was satisfied both Luke and his mother were at considerable risk of harm.

Ms Goldsbrough said it was "not in Luke's interests to have contact" with his father.

The intervention order the magistrate imposed was later varied so that Mr Anderson could see his son at sporting matches at weekends. Mr Anderson was in breach of the order by attending cricket training on the weekday he attacked Luke.

Ms Batty told the court on Monday she was unaware Mr Anderson's housemate had taken out an intervention order until she read it "in the paper the day after Luke died".

She said it was six months after Mr Anderson was charged with child pornography offences that she learned details of the charges.

She was also unaware if police ever conducted a risk assessment on her and her son to gauge if they were in danger from Mr Anderson.

Ms Batty said she felt alone in trying to enforce the intervention order against Mr Anderson and ultimately felt like "it was a waste of time including" authorities in her plans.

The inquest, which is before scheduled to run for 12 days, will examine whether there were any failures in the way Victoria Police and DHS handled the case.

Earlier, Ms Ellyard said the father of a junior cricketer had approached the net asking about Luke, but that Mr Anderson chased them away. Mr Anderson said: "He is in heaven now."

When ambulance paramedics attended to Mr Anderson after he was shot by police, he resisted their attempts and said: "Let me die."

Ms Batty will resume giving evidence on Tuesday.