An investigation into a deadly crash last month has focused on control switches that cut off fuel to an Air India Boeing jet after takeoff.

Sumeet Sabharwal, 56, was the captain on the flight, while Clive Kunder, 32, was the co-pilot who was flying the plane. Together, the two pilots had more than 19,000 hours of flight experience - nearly half of it on the Boeing 787. Both had passed all pre-flight health checks before the crash.

Air India has completed precautionary inspections on the fuel control switches on all its Boeing BA.N 787 and 737 aircraft.