Parts of the black boxes from the Egyptair Paris-Cairo flight that crashed in the Mediterranean last month have been sent to France for repairs, Egyptian authorities said on Monday.
The Egyptian-led accident investigation committee said its members would be present during the repair work on the memory units of the Airbus A320's flight data recorder and cockpit voice recorder.
The units were recovered from the sea 10 days ago, but had broken into several parts and suffered serious damage, which meant consistent readings could not be taken from them, the committee has said.
The data on the two black boxes, if it can be extracted, will be crucial to determining the cause of the May 19 crash, 290 kilometres north of the Egyptian coast, in which all 66 passengers and crew were killed.
Greek and Egyptian radar records showed that the plane veered sharply to the left and then spun around to the right in the last minutes before crashing.
No distress call was received. The pilot had communicated normally with Greek air traffic control shortly beforehand.
Also on Monday, the Paris prosecutor's office said it was opening an involuntary manslaughter investigation into the accident.
The office had already opened a preliminary investigation in mid-May.
Last month, Egyptian Civil Aviation Minister Sherif Fathy said that a terrorist act appeared a more likely cause than mechanical failure.
The Egyptian-led accident investigation committee said that work to retrieve the wreckage and body parts from the seabed was continuing.
The crash came almost six months after a Russian passenger jet broke up in midair shortly after take-off from the resort of Sharm el-Sheikh in Egypt's Sinai peninsula, killing all 224 people on board.
Russian authorities said that the incident was caused by a bomb. The Islamic State extremist group, which operates in Sinai, claimed responsibility and published a photo of a soft drink can that it said had been filled with explosives and smuggled onto the flight.
That crash devastated Egypt's tourism industry, a key source of hard currency which was already suffering due to perceptions of instability since the country's 2011 revolution against dictator Hosny Mubarak.