Charges could be laid against the boy driving a car that crashed in Ngaruawahia on Friday, police say.
An 11-year-old boy died after a car carrying seven children, aged between 9 and 14, crashed into a tree.
A nine-year-old boy remains in a critical condition, while five other children are stable in Waikato Hospital.
Detective Senior Sergeant Steve Ambler said the vehicle was travelling substantially faster than the 50km speed limit in the area.
He said inquiries were continuing to determine the driver and his culpability.
"Given the age range, driver inability or inexperience has to be a major factor in relation to this accident. I can almost certainly say there will be action taken against the driver."
Steve Amber said he could not confirm the age of the driver.
He said it was likely the boy who died was not wearing a seat belt, but the front seat passenger and driver were.