The doomed Boeing that killed 132 people when it nosedived from the sky was 'sabotaged by someone inside the cockpit', findings from the aircraft's black box have indicated.
The China Eastern Airlines 737-800 came down in the country's southern province of Guangxi on March 14.
It was mainland China's deadliest aviation disaster in 28 years, it was confirmed.
Experts originally suggested pilots aboard the passenger plane may have lost consciousness as the aircraft hurtled towards the ground before briefly waking up.
However the Wall Street Journal today claimed US officials' preliminary assessment has analysed both black boxes and made a disturbing discovery.
The government lab in Washington, DC, indicates someone in the cockpit intentionally crashed the huge jet.
Reuters are reporting that the crew is being investigated after the probe did not find any suggestion of a technical malfunction.
In April, a report issued by the Civil Aviation Administration of China confirmed no "abnormalities" had been found in the plane.
Pictures show that the crash left a huge 65-foot-deep crater in side of the mountains.
Such was the devastation, it sparked a fire in the surrounding forest.
More than 49,000 pieces of plane debris were found.
Flight MU5735 had departed the city of Kunming at 1.11pm local time and was due to arrive in Guangzhou at 3.05pm.
But as it prepared to descend, the aircraft lost altitude and dropped thousands of feet in seconds.
Despite momentarily regaining height at close to 9,000ft it hit the ground at an estimated 350mph in a hilly woodland area near the city of Wuzhou.
China Eastern grounded all of its Boeing 737-800s as a precaution.
In a statement, the airline - one of the three biggest in China - expressed "its deep condolences for the passengers and crew members who died".
Data from flight-tracking website FlightRadar24.com showed MU5735 had been travelling at around 30,000ft when it suddenly entered a deep dive at its cruising altitude speed of 523mph.
The data suggests the plane crashed within a minute-and-a-half of what caused the disaster.
Shanghai-based China Eastern is one of the country's top three airlines, operating domestic and international routes serving 248 destinations.
The twin-engine, single-aisle Boeing 737 is one of the world's most popular planes for short and medium-haul flights.
Boeing declined to comment on the US. officials' preliminary assessment.
