Emergency services were called to Clark Rd, Waitati, about 11.30am on Monday and police later confirmed the incident involved a digger.
Police confirmed this morning the man was working by himself using the digger to clear a boundary line.
A friend went looking for him after he failed to respond on the radio and subsequently found the man on the ground, police said.
CPR was attempted at the scene.
A police spokeswoman said the digger had not rolled. The police serious crash unit was also in attendance yesterday.
WorkSafe confirmed it was making inquiries.
The death has been referred to the coroner.