KEY POINTS:
Police are investigating alleged abuse of Nia Glassie's two sisters, 8-year-old Esther and 10-year-old Jessie.
They last night confirmed that they were aware of allegations of abuse of the two girls and that the allegations were being investigated as part of the inquiry into Nia's death.
"It's part of our investigation, yes," inquiry head Detective Senior Sergeant Mark Loper said.
Mr Loper would not comment on the specific allegations but said the investigation involved all five people accused of abusing Nia.
"Their relationship with other people, including other children, has always been part of our inquiry," he said.
It is understood further charges are likely in relation to the alleged abuse of Nia's sisters, who lived at the same Rotorua house as the 3-year-old.
The three girls were under the care of their mother, Lisa Kuka, but Esther and Jessie have since been placed with a relative of Ms Kuka by Child, Youth and Family.
Mr Loper would not comment on the nature of the alleged abuse of the two girls or whether they had been injured, saying the investigation was ongoing.
Nor would he say when the allegations surfaced or if they related to the same periods when Nia was allegedly abused.
