Fuel to the engines of the Air India plane that crashed last month were cut off shortly after takeoff, a preliminary report has suggested.

The report claimed that the engine one and engine two "fuel cut off switches transitioned from RUN to CUTOFF position one after another with a time gap of one second".

"The Engine N1 and N2 began to decrease from their take-off values as the fuel supply to the engines was cut off," the report added.

The situation led to a commotion in the cockpit, with one pilot being heard asking his colleague why he "cut off" the fuel supply.

PICTURED: A tail of an Air India Boeing 787 Dreamliner plane that crashed is seen stuck on a building after the incident in AhmedabadREUTERS

In response, the second pilot said that he did not do so.

It did not identify which remarks were made by the flight's captain and which by the first officer, nor which pilot transmitted "Mayday, Mayday, Mayday" just before the crash.

The preliminary report also does not say how the switch could have flipped to the cutoff position on the June 12 London-bound flight from the Indian city of Ahmedabad.

US aviation safety expert John Cox said a pilot would not be able to accidentally move the fuel switches that feed the engines. "You can't bump them and they move," he said.

Investigators still failed to rule out the possibility of sabotage being behind the Air India crash in Ahmedabad earlier this monthREUTERS

Flipping to cutoff almost immediately cuts all of the engines.

It is most commonly used to turn engines off once a plane has arrived at its airport gate and in certain emergency situations, such as an engine fire.

The report does not indicate there was any emergency requiring an engine cutoff.

The flight bound for London Gatwick crashed shortly after taking off from Ahmedabad in the Gujarat state in Western India. The crash killed 260 people, including 241 passengers and crew on board and 19 others on the ground.

It was the world's deadliest aviation accident in over a decade.

Smoke rises amidst debris after an Air India plane crashed in Ahmedabad, IndiaReuters

A spokesman from India's Aircraft Accident Investigation Bureau said: "At this stage of investigation, there are no recommended actions to Boeing 787-8 and/or GE GE.N GEnx-1B engine operators and manufacturers"

A firefighter works at the site where Air India flight 171 crashed in a residential area GETTY