The investigators have successfully extracted data from one of the black boxes of EgyptAir Flight 804 suggesting fire or other cause for the smoke detected in a toilet and the avionics bay.
Egypt's Aircraft Accident Investigation Committee said the flight data recorder confirmed previous reports of smoke on flight MS804.
"Preliminary information shows that the entire flight is recorded on the FDR, from when it took off from Charles de Gaulle airport to when the recording stopped at the place of the accident at 37,000ft," a statement said.
The recorded data is in consistency with Aircraft Communications Addressing and Reporting System (ACARS) messages referring to smoke in the lavatory and electronics room of the avionics bay, reports the Independent.
"Recovered wreckage from the jet's front section showed signs of heat damage and "thick black smoke," the Aircraft Accident Investigation Committee added.
However, the second black box - the cockpit voice recorder, is still being repaired and will then be analyzed to confirm the cause of the crash that killed all 66 people aboard.
The black boxes of EgyptAir Flight 804 were badly damaged when they were recovered in the Mediterranean Sea and the Egyptian investigators sent the mangled memory chips of the black boxes to a technical team in France last week.
Amid speculations that either mechanical failure or terrorist attack caused the crash, the investigators are looking to extract any bytes of the data to find the critical evidence needed to reveal the cause of the crash.
The cockpit voice recorder captures sounds from the flight deck, including flight crew conversation and alarms and background noise that can help investigate what the flight crew was doing at the time of the crash.
The flight data recorder gathers 25 hours of technical data from the airplane's sensors, recording several thousand distinct pieces of information, including air speed, altitude, engine performance and wing positions.
The Airbus A320 had 66 people aboard when it lost contact above the Mediterranean, shortly before the aircraft entered Egyptian airspace. The plane suddenly vanished from the radar as it soared over the Mediterranean from Paris to Cairo on May 19.
