Preliminary findings indicated the fuel switches were turned off, though it's unclear whether it was accidental or intentional and whether any effort was made to turn them back on

A preliminary report into the deadly crash of an Air India jetliner in June is expected to be released by Friday, three sources with knowledge of the matter said, with one adding the probe had narrowed its focus to the movement of the plane's fuel control switches.

The Aircraft Accident Investigation Bureau (AAIB) will make public this week its preliminary report on the Air India plane crash in Ahmedabad in which at least 260 people were killed on June 12, top Bureau officials told a Parliamentary panel on Wednesday.