The captain of the flight requested a priority landing due to a medical emergency on board and crew providedfirst-aid assistance to the passenger, Jetstar said in a statement provided to NZME.
St John was alerted to the incident around 6pm and sent two ambulances plus the Fire Service as first response to the airport. The patient was in a critical condition and received emergency treatment but died at Christchurch airport, a spokesperson for St John said.
A Fire Service southern communications spokesman said an unit was sent from Harewood Fire Station after being alerted to a medical emergency.
An aviation safety analyst based in Europe said deaths from natural causes happened on commercial flights roughly "once a week or so" across the world.
