Incredibly, neither the child nor their 9-year-old passenger were badly hurt in the crash.
Two patients were treated at the scene before being taken to Buller Health Hospital in a “minor condition”, according to St John.
Fire and Emergency southern shift manager Darryl Ball told the Herald that emergency services were called to a “van rollover” just before 1.30pm on Tuesday.
Waimangaroa and Westport fire crews had attended the scene and assisted police and ambulance.
Greymouth Senior Sergeant Mark Kirkwood told the Star the young pair appeared to have taken a family member’s van from the property where they were staying, north of Westport.
Kirkwood told the Star that questions were being asked, given the extraordinary circumstances of such a young child being behind the wheel.
Police were speaking with the children’s caregiver at the time – a grandparent – about the incident.