The Children's Commissioner believes there was little Child, Youth and Family (CYF) could do to save Moko Rangitoheriri.
The three-year-old died after enduring weeks of violent abuse at the hands of David Haerewa and Tania Shailer, who have admitted Moko's manslaughter.
The pair were originally charged with murder, but were offered a deal by Crown prosecutors.
His mother, Nicola Dally-Paki, spoke to Story last night, saying she felt let down by CYF.
But commissioner Dr Russell Wills isn't sure the department could have prevented Moko's death.
"There wasn't concern about Moko in the care of Tania before this," he says. "At this point it's hard to see how Child, Youth and Family could have done anything differently that would have changed the outcome here."
Dr Wills still has faith in CYF, despite Ms Dally-Paki's claims the organisation failed her son.
"Often people in violent relationships will listen to friends or family," he says. "If they won't, and if the kid is being harmed, then you must call Child, Youth and Family. In my experience Child, Youth and Family does investigate promptly and does keep children safe."
Prime Minister John Key agrees.
He still believes in CYF, which is undergoing a major review, and says if there are any lessons to come from Moko's death, those will be taken on board.
"On the best advice I've had, CYF acted appropriately. The situation is awful and terribly tragic and what we have to do now is make sure as we reform CYF we deal with a great range of issues -- the bigger more systemic issues about the way vulnerable young children are handled and supported," he says.
But he didn't think there needed to be a wider review into child abuse and the way cases are handled in the courts.
"For the most parts the courts follow the rules set by Parliament. If you want to make changes then Parliament always has the right to issue longer sentences.
The major issue is to make sure the changes to CYF don't allow young people to end up in such situations in the first place.
Shailer and Haerewa will be sentenced for Moko's manslaughter in June.
But Labour's children's spokeswoman Jacinda Ardern says the deal shouldn't have been done and justice would have been better served by a jury.
"Our law was not the problem here. The plea deal was.
"Coroner [Wallace] Bain, who will conduct an inquest into this case, has drawn comparisons with Nia Glassie. Moko was the victim of a sustained attack, and what has been described as torture," she says.
"This case was horrific, and it is hard to see how this could have been interpreted as anything other than murder."
Newshub.