Leaked data has reportedly emerged indicating that Flight MS804 was on fire before it crashed, as smoke alarms were sounding for almost three minutes before it began its rapid descent.
The new information suggests that a fire on board the EgyptAir plane is a more likely reason for the crash than a bomb, although experts have not ruled out the use of an 'incendiary device'.
While Egyptian officials continue saying that they suspect terrorism, no group has yet come forward to claim credit as theories as to the cause of the crash continue to circulate.
It comes as hundreds of mourners gathered to offer prayers for the 66 passengers and crew killed in the EgyptAir disaster.
The leaked data was filed through the Aircraft Communications Addressing and Reporting System (ACARS), a data link for sending messages between planes and ground facilities.
An ACARS screen grab published by air industry website The Aviation Herald shows time stamps that appear to match the time the aircraft lost contact with controllers.
According to the leaked data, smoke alarms in the lavatory behind the cockpit first began sounding at 00.26GMT. Less than a minute later, smoke was also detected in the avionics [electronics].
The final two alerts from the plane indicate faults with the FCU - the flight control unit used by the pilot to input instructions into the flight computer - and the SEC 3 - the computer that controls the plane's spoilers and elevator computers.
The Aviation Herald claimed to have received the data from three independent channels, which were unidentified, but there has as yet been no official confirmation.
The ACARS screen grab provided information about smoke and heat on a window near the co-pilot and in the lavatory, which was behind the cockpit, according to CNN aviation analyst David Soucie.
'If there's fire on board the aircraft, in this area which the ACARS indicates, then something was close to the cockpit,' Mr Soucie said.
ACARS does not provide a cause of the crash, but Mr Soucie said it was significant that the data was sent over a period of one to two minutes.
'Now if it it was a bomb, the characteristic bomb... would have ruptured the skin of the aircraft,' he said.
'This is not the indication you would have had, because a bomb that would do that would be instantaneous, and these reports would not have gone over two minutes like they do.'
The analyst added that a fire in the front section of the plane may well have affected the communications equipment.
By Nick Fagge, Simon Tomlinson and Imogen Calderwood
Editor's note: This article has been edited from the original.
