According to a media report, the crash of a passenger plane in China with 132 dead could have been caused intentionally.
This is indicated by flight recorder data examined by US investigators, as the Wall Street Journal newspaper reported on Tuesday.
"The plane did what it was told to do by someone in the cockpit," the newspaper quoted a source familiar with the US authorities' preliminary assessment as saying.
China Eastern Airline Flight MU5375 was en route between the Chinese cities of Kunming and Guangzhou on March 21.
Over the Guanxi region, the machine, a Boeing 737-800, suddenly crashed from a height of around 8,800 meters and crashed on a mountain slope.
All 132 occupants died.
Flight recorder data sent to USA
After the crash, the Chinese civil aviation authority CAAC took over the investigation into the cause of the accident.
At the end of April, she announced that she had completed a preliminary report - but without giving any information on a possible cause of the crash.
In accordance with international air traffic regulations, the US Air Traffic Safety Administration NTSB provided technical support for the investigation, which is why the data from the flight recorder was transmitted to the USA.
According to the Wall Street Journal, this data shows that one of the pilots, or someone who had entered the cockpit, used control inputs to force the plane into a nosedive and cause it to crash.
According to the newspaper, US authorities believe the pilot is more likely to be responsible.
The CAAC, on the other hand, had announced that there was no suspicion against the pilot.
According to the Wall Street Journal, US authorities see their findings underpinned by the fact that Chinese investigators have so far not pointed out any problems with the aircraft or airspace surveillance.
A CAAC statement said the crew conducted all safety checks, there were no hazardous materials on board and the flight did not encounter problematic weather conditions.
Strict control from Beijing
After the plane crash in March, the Chinese Communist Party was quick to keep information about the crash under control.
After the accident, the Chinese Internet regulator announced that it had removed a large amount of "illegal information" from the Internet.
The crash was the deadliest plane crash in China in three decades.
Security in the country is very strict.
Plane crashes caused by pilots are extremely rare.
In March 2015, the co-pilot of a German airline, Germanwings, intentionally crashed a plane in the French Alps.
144 passengers and six crew members died.
Since then, the European aviation safety authority AESA has increased medical care for pilots, especially with regard to their mental health.