The preliminary finding gives investigators a new line of inquiry as they study a crash that killed all but one of the plane’s passengers.

Investigators in India are studying the black boxes of a Boeing 787 Dreamliner after recovering them from the aircraft wreckage to ascertain the cause of last week's plane crash that left at least 270 people dead.

With about 25 per cent of the crash victims being international citizens, liabilities against Air India and Boeing could exceed significantly, should they be found in violation of international law