A two year-old boy has survived uninjured after his grandfather unwittingly drove him 20 kilometres on his trailer in Golden Bay.
Police say the toddler hung on down the twisty Takaka Hill road - all the way to Motueka - before being discovered.
Senior Sergeant Grant Andrews says police received calls about the boy on the trailer about 11am on Thursday.
He says the grandfather had pulled in as police arrived, shocked to discover the boy, whom he had not seen as the wire cage trailer was covered at the front.
The boy had climbed in unbeknownst to his granddad.
Senior Sergeant Andrews says the boy could have got out the top, because that was obviously where he had climbed in.
His parents had realised he was missing, and had started looking for him.
Senior Sergeant Andrews says the matter is at an end for police.