In impassioned submissions at the inquest into the death of Taupo toddler Moko Rangitoheriri, a former national Women's Refuge chief has demanded to know what's changed since a similar case a decade ago.

Presiding Coroner Wallace Bain replied: "Sadly, not a lot."

He was hearing from Merepeka Raukawa-Tait, who also gave evidence at the inquest into the death of Nia Glassie 10 years ago - another battered infant who died at the hands of caregivers.

Family violence campaigner Ms Raukawa-Tait told the inquest she understood while some of the recommendations made after that probe had been implemented, there hadn't been major change.

She also acknowledged the recent establishment of the Ministry for Vulnerable Children, but said it was the ambulance at the bottom of the cliff.

"We should be putting some of those dollars (that go to the Ministry) into the front end and work with the families," she said.

Moko died at Taupo in August, 2015, after being severely beaten by caregivers Talia Shailer and David Haerewa.

Both are serving 17-year jail terms for the three-year-old's manslaughter.

The inquest, which began with two days in August, resumed in Rotorua on Tuesday for expert evidence to be heard.

Paediatrician Johan Morreau described being seriously disturbed by the violence Moko suffered.

"In my career I've not seen a comparable case."

He said New Zealand had allowed its standards of support and care for children to fail.

The ministry's Bay of Plenty regional manager, Tayelva Petley, and Detective Inspector Mark Loper gave evidence of changes made by both organisations since Nia's death

Inspector Loper told the court there'd been 94 New Zealand homicides involving children between 2007 and 2015.

He emphasised a cultural shift in police practice since Nia's death with staff now looking at the needs of the victim, their family and home environment.

Ms Petley outlined a raft of changes made within the Ministry since Moko's death.

She said the Taupo organisation overseeing Moko and Shailer had relinquished its contract and a new family support provider appointed.

The inquest opened with a minute's silence for Moko.