An adventurous toddler turned stowaway on his grandfather's trailer and was only discovered 20 kilometres later.

Motueka police now want to thank members of the public for their quick response.



A West Coast man left a family member's home near the summit of the Takaka Hill towing a trailer just after 11am today.

Unbeknown to the man his two-year-old grandson, who lives at the Takaka Hill address, had climbed into the trailer. The child was obscured from the driver's view.



Several members of the public saw the toddler sitting in the trailer as the man drove down the hill and contacted police.



The man had driven to Motueka before stopping, where he was met by police.



Senior Sergeant Grant Andrews said the grandfather was horrified when he discovered he had driven more than 20km down a winding hill with the young child in the trailer.



"He immediately phoned the boy's parents, who were looking for the child.



"I'm just pleased to be able to say the little boy has survived the ordeal unharmed. I'd also like to thank everyone who notified Police quickly after seeing the child in the trailer," he said.