The captain and crew of the Indigo Airlines plane, en route from Singapore to New Delhi, administered first aid to the passenger, 70-year-old Indian national Ramesh Kumar Brasin, but decided his condition was severe enough to warrant immediate hospitalisation.
The headed for the nearest airport, which was Phuket. The plane was met by an ambulance which took Mr Brasin to Thalang Hospital where, despite emergency treatment, he died 12 hours later.
The cause of death was listed as heart failure.