Malachi Subecz's grieving family will mark his sixth birthday this weekend no closer to knowing what agencies could have done to prevent his murder.

Four months since Children's Minister Kelvin Davis announced a sweeping review into how government departments could have intervened to prevent Malachi's murder at the hands of his caregiver, Michaela Barriball, Malachi's family say every day spent waiting adds to their heartbreak.

'Oranga Tamariki came around and they were apologetic and stuff, they were really nice but we'll see what happens when the report comes out,” said family spokesperson Helen Menzies.

'The waiting is the worst, because we want change, and in the meantime we're seeing more children being hurt.

'We want proper, positive change for other New Zealand kids, and we can't afford to wait.”

Malachi died on November 12, 2021, aged 5, following prolonged and horrific abuse at the hands of Barriball, whom his imprisoned mother had entrusted with his care. Barriball was sentenced to life imprisonment with a minimum non-parole period of 17 years on June 30.

In sentencing, Justice Paul Davison admonished those who could have acted to try and prevent the child's abuse. 'Adults could have taken steps to intervene and report what was happening, this is the clear lesson,” he said.

The Review of Children's Sector Response to Abuse is being led by Dame Karen Poutasi, and will look across every agency that had contact with Malachi to see how his death could have been prevented.

The family received a letter from Poutasi on August 5 inviting them to contribute to the systemic review.

Poutasi has asked the ministries of education, corrections, justice, health and social development to conduct individual reviews into their interactions with Malachi, to identify how his death could have been prevented. The terms of reference for her review state it will also recommend changes to the overall system to prevent similar tragedies happening again.

This is due for completion in December 2022.

A separate Oranga Tamariki practice review, led by Chief Social Worker Peter Whitcombe into Oranga Tamariki's own handling of the events leading up to Malachi's murder, will feed into her report.

Davis said he understood the Oranga Tamariki review was nearly finished.

In a written statement, Oranga Tamariki said the review team were continuing to meet with Malachi's whānau to hear their perspective, which is an essential part of the practice review.

Malachi would have turned 6 on September 28. His family is planning to gather for a dinosaur-themed tribute this weekend. 'If he was alive that's when we would have had it, when he was home from school.”

The family were stuck in limbo, Menzies said.

'I'm still grieving, I'm here but no-one's home. I still wake up hearing his breathing, I can't find anything positive from the negative, and that's what's got us stuck. It's taken its toll.”

The Wellington-based extended family previously told Stuff they contacted Oranga Tamariki and the courts to register their fears for Malachi's safety in Barriball's care within a week of his mother being jailed on June 22, 2021.

They say they were fighting for custody and questioned the actions of police and the judiciary, asking why he was allowed to leave court with his killer.

-Michelle Duff/Stuff.