"Look at that," Rod Vaughan says, pointing to a jagged horizontal gash the length of the windscreen of his wrecked rented plane.
The veteran TV journalist, who lives in Katikati, said the gash showed the path of an object that shattered the plexiglass at 1600 feet, forcing him to make a terrifying emergency landing in the middle of a cropped maize field, his adult son Richard bracing for impact in the passenger seat.
Vaughan was certain that object could only have been a drone.
Less than 24 hours after Wednesday's mid-afternoon crash, the broadcaster - white bandages wrapped around his head - returned to the scene with his wife, Lois, in the hope of retrieving some effects from the wreckage and examining the evidence.
Looking at the battered aircraft - a two-seater Aeroprakt Foxbat light plane Vaughan could not praise highly enough - it was hard to believe they escaped with only minor injuries.
Both father and son had contusions and bruising from the harnesses they were left hanging upside down in when the nose wheel broke on impact, flipping the plane over its nose on to its roof. Vaughan had a cut to his scalp that bled rather profusely.
Neither man saw the object that struck the windscreen but Vaughan was certain it came from the side as they were flying over the mine in Waihi.
A bird would have left feathers and blood. A high-velocity bullet was possible but incredibly unlikely.
"The most probable explanation is that it was a drone," he said.
His theory has been backed by a flying instructor at the club Vaughan had rented the plane from, and one of the first on the scene.
Hauraki Aeroclub chief flying instructor Cliff McChesney said members had checked the aircraft and there was no sign of feathers or any other suggestion a bird had impacted the windscreen.
"Something has hit it and that something is pretty heavy, the windscreen is 4mm to 5mm thick and it has imploded," McChesney said.
He said there were often drones in the area the plane was, as the large open pit mine was a popular spot to photograph.
"I would say there's a drone up there every day at some time."
Both McChesney and Vaughan were concerned about the growing popularity and availability of drones, and the danger they could pose to pilots.
Vaughan said that if his theory proved correct, as far as he was aware it would be the first time a drone had caused a plane to crash.
Tighter rules needed to be in place regarding the use of drones, he said.
"It's quite incredible, the number of drones being operated by all manner of people.
"The regulations in New Zealand I think are incredibly lax. We are right behind the eight-ball. This was an accident waiting to happen."
He said he hoped the crash might spark a national debate about drones.
A Civil Aviation Authority spokesperson said on Thursday the regulator was investigating the crash, but would not comment on speculation it was caused by a drone.
- Additional reporting NZME