A 17-month-old boy is fighting for his life in Starship Hospital after suffering severe head injuries.

The Herald can reveal the toddler's mother has had five children previously removed from her care by Oranga Tamariki.

The Auckland toddler was admitted to Starship Hospital with serious head injuries on Sunday night.

Hospital staff alerted police, believing the child's injuries may have been deliberately inflicted.

No one has been arrested or charged at this stage.

Detective Senior Sergeant Geoff Baber confirmed police were notified at 7.30pm on Sunday. 

"A scene examination is being carried out at an address in Auckland's central business district," he said.

"Police are continuing to piece together what has led to this child's injuries which we believe at this stage are non-accidental.

"Police are speaking to several people in relation to this matter and there is no further information available at this stage."

Police would not comment on the background of the child's mother or whether she had been spoken to. 

But the Herald understands the toddler is her sixth child - and her five older children have all been removed from her care.

Oranga Tamariki has been contacted for comment. 

Earlier this month the Children's Commissioner Judge Andrew Becroft announced a review into Oranga Tamariki's child uplift policies relating to care and protection issues for Maori babies.

It follows controversy over the attempted uplift last month of a young Maori mother's baby from Hawke's Bay Hospital that today saw Minister for Children Tracey Martin announce an internal inquiry.

The "thematic review" by will look specifically at policies around Maori infants aged 0-3 months.

Judge Becroft said while the review would initially focus on the 0-3 months age group, he could not rule out extending the review to older children.

He said his office had a statutory mandate to investigate.

"If we didn't do it we would be asleep at the wheel," he said.

Earlier the same day Minister for Children Tracey Martin announced an internal inquiry by Oranga Tamariki into its processes specifically around the Hasting family's case.