Police in Invercargill are concerned for the safety of an 11-year-old boy, believed to be with his stepfather in breach of a parenting order.
They are keen to find Mike Zhao-Beckenridge, who has been missing since last Friday.
The police believe the 11-year-old left his school in Invercargill around lunchtime on Friday and was not there around 3pm when his mother went to collect him.
He is believed to be with John Beckenridge, 64, who is also known as John Robert Lundh, Knut Goran Roland Lundh and John Bradford.
Police said they could be anywhere in New Zealand and were thought to be travelling in a dark blue Volkswagen Touareg, registration number DUY263.
Mike is 1.65cm tall, of solid build and of Asian descent.
John Beckenridge is 1.75m, of medium build and of Swedish descent.
Detective Sergeant Mark McCloy said it was unusual for the pair to not be in contact with family or friends.
He said Mike was meant to be in the sole care of his mother.