A preliminary report released last week included detail about the fuel, saying that the fuel to the plane's engines appeared to have been shut off.

The U.S. assessment is not contained in a formal document, said a source, who emphasized the cause of the deadly crash remains under investigation.

Speculation is growing about the cause of the Air India plane crash last month after a report suggested the pilot deliberately cut off the fuel. A cockpit voice recording suggests that the captain, Sumeet Sabharwal,