Police say the vehicle involved in the horror crash in Matamata that left four children with critical injuires had been stolen from Hamilton.
Their investigation also suggests the vehicle was linked to a burglary on Monday evening - before the crash.
Police say the five children, all aged between 10 and 13, were found outside of the crashed car on Morrinsville-Walton Rd just before midnight on Monday.
In an update on Tuesday afternoon, Waikato District Commander Superintendent Bruce Bird said police are assessing all information.
"It is too early to provide detail on the cause of the crash itself other than to say speed appears to be a likely factor," he said.
Four children remain in a critical condition in Waikato Hospital's intensive care unit. One of them is expected to be transferred to Starship Children's Hospital later on Tuesday. A fifth child remains stable in Waikato Hospital.
Supt Bird added police aren't looking for anyone else over the crash, and police had no interaction with the vehicle prior to it crashing.
