A farmer in the Bay of Plenty says 16 of his cows were killed when a violent twister brought down power lines on his farm on Friday.
The tornado ripped through the Jackson Rd area, east of Opotiki, accompanied by heavy rain and hail.
It also demolished two barns, scattered trees and wrecked hundreds of metres of fencing.
Farmer Graham Collier said the twister ripped out several power-poles, dropping high-voltage power lines that electrocuted 16 in-calf cows.
"There was a lot of rain and hail coming down and then the windows on the house and the ranch sliders started rattling and moving - some of them by several inches. It was quite scary," Mr Collier said.
"I went outside and checked the cowshed. A couple of 25,000-litre water tanks had been lifted by the twister. They were empty but lashed to the fence."
The tornado took the tanks and fence, and dragged them through two other fences, damaging more than 300 metres in all, Mr Collier said.
Mr Collier said he noticed the wires and a gate were still glowing and was not able to do anything until the power was shut down.
Horizon Energy operations manager Barry Cooper said he learned of the event yesterday and had launched an investigation to determine what had happened.
Other damage was caused to neighbouring properties.