If there is a risk of one parent taking a child out of New Zealand without the other parent's consent, an Order Preventing Removal of Child from New Zealand (OPR) can be obtained within 24 hours. The court is able to place Border Alert on the child's passport to stop the child from being removed.
If your child has been taken overseas without your agreement you should contact the police and report the child as missing and apply through the Hague Convention for return of the child.