CAIRO, Jul 2 (Aswat Masriya) -  Egyptian investigators said on Saturday that board components of cockpit voice recorder (CVR), one of the black boxes of doomed EgyptAir flight, were replaced to enable the reading of recorders of the CVR memory units.

Egypt sent the flight's black boxes, the CVR, and the flight data recorder (FDR), to France to be repaired after they were found damaged in the Mediterranean.

The black boxes are crucial for piecing together the causes of the plane crash which are still unknown more than a month after the jet plunged into the sea.

The passenger flight crashed about 280 km off the Egyptian seacoast en route from Paris to Cairo. It was carrying 66 people on board.

Last week, investigators downloaded data from the FDR and preliminary information showed that the entire flight was recorded on the FDR since its take off from Charles De Gaulle airport until the recording stopped at altitude 37,000 feet above the Mediterranean, where the crash occurred, said the committee in a report.

The data retrieved also showed consistency with ACARS messages of lavatory smoke and avionics smoke," said the investigation committee in reference to Aircraft Communications Addressing and Reporting System which allows aircrafts to communicate with ground stations during flight.

According to Reuters, the plane had sent a series of warnings indicating that smoke had been detected on board through ACARS.

Some of the recovered wreckage of the front section of the aircraft showed signs of high temperature damage and soot, accordingly analysis will be carried out to find out the source of those signs, said the committee.