The death of a 39-year-old at an onshore oil rig in Taranaki today remains unexplained.
The man collapsed on the oil drilling derrick approximately 40 metres off the ground at the Mangakewa E Wellsite in Tikorangi, Sergeant Grant Roper of New Plymouth Police said.
Emergency services were called to the scene, near Waitara, around 8:10am today.
Workmates performed CPR until St John ambulance staff arrived and the man was pronounced dead at the scene.
He was employed by MB Century, the company with the contract to carry out the work at the Todd Energy site.
MB Century chief executive Marcel Manders said the death had been referred to the coroner.
"There weren't any indications as to why he collapsed,'' he said.
Mr Roper said the man did not fall from the structure, and that police had not ruled out a medical emergency being the cause of death.
"I would urge against speculation at this stage into the cause of death due to the place it occurred,'' he said.
Police and Work Safe NZ are investigating the incident.
Chris Matthews of the St John central communications centre said there was nothing the ambulance crew could do for the man when they arrived.