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.

In 2012 a Boeing jet was deliberately crashed in the Sonaran desert, Mexico and filmed it for television. The test revealed the safest seat to sit in.

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