Police released the name of the nine-year-old boy who died when his go-kart hit soft sand and rolled on the beach near Kaka St, Ahipara, just before 5pm on Saturday.
The name of the boy is Rowan Willis, of Auckland.
Speed is believed to be a factor and as Ninety Mile Beach is a highway the death would be included on the region's road toll, Northland road policing manager Inspector Murray Hodson said.
Two ambulances from Kaitaia and paramedics arrived to find the boy receiving CPR from bystanders, St John Mid North manager Mark Going said.
"We continued with resuscitation attempts, supported by the local fire service, but the resuscitation was not successful."