"It's hay that's combusted and caught on fire that's been baled three weeks ago.
"It ignited into some silage tyres, so it jumped into them about 200m away and burnt them. That's pretty much it."
He said the fire, which covered about 2ha, was contained late yesterday afternoon and at least one digger would be used to dig a large hole to bury the hay.
Senior Constable Peter Scott, of Kurow, said police became involved after two drones were seen in the area. Their presence grounded the helicopters for safety reasons.
They could be controlled from 5km away so it was difficult to find those controlling them, he said.
After a safety meeting, the helicopter crews decided they would fly again, and there were no further sightings of the drones.
"I'm hoping that the people who were flying them realised that they were being foolish once they saw that the helicopters were grounded."
Scott said drones could have a massive impact on other people's safety.
"To fly drones in an area where helicopters were dropping water buckets on a serious rural fire was very foolish."
Police also contacted Glide Omarama to ensure gliders stayed away from the area.
Fire and Emergency New Zealand shift manager Andrew Norris said high winds hampered crews' early efforts.
