SHANGHAI, May 6 (Reuters) - The U.S. National Transportation Safety Board (NTSB) released data this week indicating the fuel supply to both engines of a China Eastern Airlines 600115.SS flight was switched off before the jet plunged into a hillside in southern China in March 2022, killing all 132 people on board.

The data, which was released by NTSB in response to a freedom of information request and originated from the plane's flight data recorder, showed the fuel switches for both engines moved simultaneously from the run position to the cutoff position before the jet descended.

“It was found that while cruising at 29,000 feet, the fuel switches on both engines moved from the run position to the cutoff position. Engine speeds decreased after the fuel switch movement,” the NTSB report said.

Fuel switches on Boeing 737 aircraft are physical controls regulating fuel flow to the engines, and a pilot must pull the switch up before moving it from run to cutoff.

The crash of the Boeing BA.N 737-800, operated as China Eastern flight MU5735, was China's deadliest air disaster in decades.

Chinese regulators have not released a full report detailing the findings of their investigation into the crash and have given no update into their investigation for more than two years.

The Civil Aviation Administration of China (CAAC) and China Eastern Airlines did not respond to Reuters' request for comment on the report and a spokesperson for China's Ministry of Foreign Affairs declined to answer a question about the U.S. findings at a regular press briefing on Wednesday.

The flight data recorder is one of the two black boxes recovered from the wreckage. It was sent to the NTSB laboratory in Washington for analysis because Boeing is an American aircraft manufacturer.