Police confirmed Nicolas John Teague, 39, collapsed while on the oil drilling derrick about 130 feet in the air.
The rig is located at the Mangakewa E wellsite in Tikorangi.
Emergency services were called to the site at 8:30am Sunday.
Teague was pronounced dead at the scene.
“Todd Energy expresses its condolences to the deceased’s family, friends and colleagues,” a statement from the company said.
The incident has been referred to the local coroner and is under investigation by the police and WorkSafe New Zealand.