A Hawke's Bay MP has hit out at criticism of Oranga Tamariki's handling of a boy brutally beaten in his Flaxmere home saying they are "damned if they do and damned if they don't".

The Ministry, which last year had to apologise for the handling of an attempted uplift of a baby at Hawke's Bay Hospital, now finds itself in the eye of another storm for returning a boy to Ramsey Cres.

The boy, who had been previously injured in what some family claimed was a bouncy castle fall, was returned to immediate family and then seriously injured again on January 29.

Newsroom reported OT allegedly allowed the boy's return without full consultation with the wider family, with some opposed to it.

Prime Minister Jacinda Ardern said what happened to the boy was a "tragedy".

"It's affected a young boy, the most vulnerable people in our society are children," Ardern said.

"We need to get to the bottom of what happened here, and we need to try and prevent this kind of harm ever happening again."

Oranga Tamariki spokeswoman Alison McDonald said the agency's priority now was to focus on the boy and his recovery.

"Because of that, our comments will be limited to protect his privacy and to acknowledge the sensitivity of the ongoing police investigation," McDonald said.

"In January this year, following extensive work with the family over many months, Oranga Tamariki was satisfied there were sufficient supports from wider whanau and professionals for the boy to be at home.

"By then, his family had actively engaged in a range of services. Decisions like this are never made in isolation," she said.

National MP for Tukituki Lawrence Yule said it was a tough situation for the agency to find themselves in.

"We shouldn't kid ourselves into thinking Oranga Tamariki can keep all children safe. They can't," Yule said.

"Oranga Tamariki is involved in situations when sadly the rightful carers are either incapable, or have ignored or walked away from their fundamental responsibility for looking after children in their care," he said.

The four year-old boy who remains in Starship Hospital in a stable condition, more than three weeks after the incident, suffered the worst injuries Detective Inspector Mike Foster has seen in his 30 years of policing.

Yule said Oranga Tamariki had to maintain a "very difficult" balance in allowing children to be with their family versus the risk the same family could be to the child.

"We wouldn't need Oranga Tamariki if all people took their parenting responsibility seriously from conception to adulthood," he said.

"Most parents do, but a significant number do not. It is easy to blame everybody else including state agencies.

"Very few cases of harm such as the hideous injuries to the four year-old in Flaxmere have ever been caused directly or indirectly by state agencies."

He said he would continue to support them in the "very challenging" work they did.

"Oranga Tamariki is caught in the scenario 'damned if they do and damned if they don't'."

Kaumātua and community leader, Des Ratima, told Heather du Plessis-Allan that there is a close whanau connection, but that he understands only the father and step-mother were at the house at the time. 

He said that he has an "informed picture". "In June of last year, there was an incident with this four year old. That occurred in Auckland. There was an investigation by the Police and Oranga Tamariki." 

Ratima said that the boy had been staying with his grandmother and had been recovering well, before in December he was uplifted and returned to his father. 

"The wider family had already said through the plans that they did not want the baby to be back in the care of the father and step-mother." 

He said he is "livid" about the situation, as it took just eight months between the June incident and the injury in January.