A cockpit recording of dialogue between the two pilots of the Air India flight that crashed last month supports the view that the captain cut the flow of fuel to the plane's engines, said a source briefed on U.S. officials' early assessment of evidence, Reuters reported.

The first officer was at the controls of the Boeing 787 and asked the captain why he moved the fuel switches into a position that starved the engines of fuel and requested that he restore the fuel flow, the source told Reuters on condition of anonymity because the matter remains under investigation.

The U.S. assessment is not contained in a formal document, said the source, who emphasized the cause of the June 12 crash in Ahmedabad, India, that killed 260 people remains under investigation.

There was no cockpit video recording definitively showing which pilot flipped the switches, but the weight of evidence from the conversation points to the captain, according to the early assessment, according to Reuters.