It is thought a dog may have bumped the handbrake of a house bus parked near Queenstown yesterday evening, resulting in the vehicle rolling 10m backwards into a ditch.
Sergeant Tracy Haggart, of Queenstown, said the bus was parked in a gravel bay at the side of the Glenorchy-Queenstown road while the occupants, a New Zealand family, drove into town in a vehicle that they had been towing behind the bus.
It appeared that the family's dog, which had been left in the bus, had been in the driver's seat and ''jumped around'', Sgt Haggart said.
The handbrake was a lever on the dashboard and was ''easy enough'' to flick from side to side.
The bus had rolled backwards into the ditch, partially blocking one lane of traffic before a fire truck towed it out.
The back of the bus, which houses the engine, was damaged in the incident. The dog was unhurt.