Egypt’s Aircraft Accident Investigation Committee have started work on the black box flight recorders from the EgyptAir plane that crashed in May.
Investigators told Reuters that it would take "lots of time and effort" to fix the two damaged recorders, which hold flight data and recordings from the cockpit.
The two recorders were recovered this week, and analysis is expected to give investigators more insight into the crash.
Flight MS804 disappeared from radar on 19 May during a flight from Paris to Cairo, before crashing into the Mediterranean, killing all 66 passengers and crew on board.
The committee have said they are now conducting electrical tests on both memory units - a necessary step before analysis of the data can begin.