An Air India executive is still urging its staff not to jump to any conclusions as the investigation into the crash that killed 260 people last month continues. A preliminary report into the June crash found that the plane's fuel control switches had been flipped off one by one.

The CEO of Air India sought to draw a line under rife speculation around the cause of last month's air disaster in Ahmedebad, saying the preliminary investigation had ruled out a mechanical cause for the crash.

Air India CEO Campbell Wilson said there were “no mechanical or maintenance issues with the aircraft or engine."