A person has died after becoming trapped in a potato harvester near Pukekohe.

Police confirmed a person has died after a workplace accident at a farm in Puni.

Fire and Emergency NZ said they were called to a property on Settlement Rd, near Puni, by ambulance to help at about 12.47pm today.

A St John spokeswoman confirmed the incident involved a man.

A tractor and attached harvesting machine are sitting in a large field of potatoes beside Settlement Rd.

Four marked police cars, several unmarked police cars, two fire trucks and one ambulance are present.

Police and emergency services at the scene near Pukekohe. (Photo / Jason Oxenham)

The police are restricting the flow of traffic on the quiet rural road which is flanked by market garden fields.

A Settlement Rd resident told the Herald he drove past the scene where up to three fire appliances, two ambulances and police were gathered.

The resident said up to 12 firefighters were gathered around the harvester.

"Some of them were lying down looking up underneath it."

The man said workers at the potato farm had gone and only emergency services were on scene.

The resident said the potato farm owners were responsible people who also notified neighbours of events and kept the area tidy.

- additonal reporting AAP