Senior Sergeant Anthony Bond, of Dunedin, said the 28-year-old man drove his digger onto his truck after he had finished working at an empty property, in Kea St, at 11.25am on Friday.
As he operated the hydraulic deck to level the truck, the weight was too much and the truck started to roll downhill, still carrying the digger.
The man hung off the side of the truck and attempted to stop it by accessing the brakes.
With the man still holding on, the truck smashed through two concrete power poles before coming to a stop.
The Police Commercial Vehicle Safety Team attended and would investigate potential mechanical fault, Snr Sgt Bond said.
Police on Friday said no injuries were reported.
Power was off for about 10 customers but was restored later that same day.
