Oranga Tamariki will investigate its practices and potential failings of care in the months before the murder of five-year-old Malachi Subecz at the hands of his caregiver Micheala Barriball.

Malachi's extended family, based in Wellington, told Stuff this week they had alerted the child protection agency to 'grave concerns” for Malachi's safety twice in the months before his death.

This included providing them with photographs of bruises, they say.

In a statement, Oranga Tamariki Chief Executive Chappie Te Kani says an independent reviewer will work alongside Chief Social Worker Peter Whitcombe to investigate how Oranga Tamariki handled the case.

'I am committed to understanding where we may have failed Malachi and his whānau and I am resolved to fixing any failures in our systems.

'The Chief Social Worker's investigation will look at what we knew, how we responded and whether the decisions made based on the information was appropriate. It will also consider whether our current assessment procedures and processes need to be modified.”

Te Kani says he's in touch with chief executives in other ministries, including police and education, on the matter.

The Tauranga daycare where Malachi attended took photographs of bruises and other injuries caused by his abuse in late September, more than a month before his murder.

These were not made available to police, and Oranga Tamariki has declined to say whether it had them in its possession.

Five-year-old Malachi Subecz was killed by his Oranga Tamariki caregivers while his mother was in prison. Photo: Jericho Rock-Archer/Stuff.

Malachi was taken to hospital as result of blunt force trauma injuries inflicted by Barriball on November 1 and died in Starship Hospital on November 12, 2021. He had been living in a cabin at the back of a Te Puna property.

Barriball had been caring for Malachi since his mother had been imprisoned on June 22, at the wishes of her and his mother.

Family spokesperson Helen Menzies, who say the extended family were fighting for custody, also this week criticised police and Oranga Tamariki for their lack of involvement at the time Malachi's mother was sent to prison, with Malachi attending court that day.

They say he was allowed to walk from the room with his killer.

Barriball pleaded guilty to murder in Tauranga High Court on Wednesday, May 4, with her sister Sharron Barriball previously found guilty of attempting to pervert the course of justice.

The summary of facts show how the last months of Malachi's short life were characterised by horrific and sustained physical and psychological torture.

Speaking on Newshub's The Nation current affairs programme on Saturday, Minister for Children Kelvin Davis said the case was 'complicated,” and involved more than one agency.

Minister for Children Kelvin Davis told the Nation the case was 'complicated” but answers were needed. Photo: Robert Kitchin/Stuff.

'It is too soon for me to jump to conclusions but if the practice has not been good enough then I expect those agencies... and I don't care who they are, and I'm sure that my ministerial colleagues will agree with me... that those agencies will be expected to change what they've done.”

Asked whether heads would roll, Davis says they have to wait for the chief social worker's investigation to be completed.

The investigation will address whether agencies should have done more after Malachi's whānau contacted Oranga Tamariki over concerns he was being abused in care, Davis says.

It is also needed to plug gaps in the system, such as who checks on the care of children when a parent is in prison, he said.

Malachi suffered daily assaults by Barriball, who was receiving a benefit to look after him, the court summary stated. The abuse included slapping him in the face, head and body, and pushing him into walls and onto the ground.

Malachi would tell Michaela Barriball he didn't want to live there, and began soiling himself. He was punished by being stripped to his underwear and locked outside.

He was found injured at the Te Puna property on November 1. He was treated in Tauranga Hospital and later airlifted to Starship Hospital in Auckland, where he died on November 12.

Barriball has been convicted on a charge of murder, and failing her legal duty to care for someone under the age of 18.

She's also been convicted for injuring with intent to injure and intentionally causing suffering, namely physical and verbal abuse, failing to provide medical assistance, and causing him to be malnourished.

Both Barriball sisters will be sentenced on June 30.

Te Kani says if Oranga Tamariki has failed Malachi, he will own it, and the agency will change.

'I appreciate this will not fill the hole in the hearts of those that loved Malachi. I don't think anything I or Oranga Tamariki does will be able to do that.

'But I do want to assure Malachi's whānau that, regardless of the outcome of this or any other reviews or investigations, Malachi will be a constant reminder of why Oranga Tamariki needs to do better and the entire children's system needs to be better.”

-Stuff/ Michelle Duff and Liz McDonald.