Investigators have recovered the cockpit voice recorder and flight data recorder from a Boeing MD-11 freighter that crashed on take-off from Shanghai Pudong airport on 28 November.
"Both recorders have reached Beijing, and they are being analysed," says an official in the Civil Aviation Administration of China (CAAC).
The exterior of the recorders has some damage, he adds.
Cargo carrier Avient Aviation was operating the aircraft, which had seven crew members on board. Three died and the remaining four were hospitalised.
It is still not clear if the aircraft, local registration Z-BAV, was airborne before it crashed. The CAAC had previously only said it skidded off the runway.
"Investigations are still going on in Shanghai and the circumstances are still unclear," says the CAAC official.
The aircraft was operating a charter freight flight and was carrying consumer products such as electrical goods and clothing, says Avient. Chinese media reports say the aircraft was bound for Bishkek, the capital of Kyrgyzstan.