Exactly what has happened and how the person has been injured were not yet clear, he said. Police are also only describing it as an "incident" at this stage.
A police spokeswoman said: "A person has been seriously injured [and] the Westpac Helicopter is responding."
St John said it sent out one ambulance vehicle and a rapid response unit to the scene.
A spokeswoman confirmed one person was treated with serious injuries. They were eventually airlifted to Auckland City Hospital in a serious condition.