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.

(Reuters) -Investigators believe the Air India Boeing Dreamliner had its emergency-power generator operating when it crashed last week in India's Ahmedabad, the Wall Street Journal reported on Wednesday citing people familiar with the probe.

The black boxes will provide cockpit conversations and data related to the plane's engine and control settings to investigators and help them in determining the cause of the crash.