It is improbable that an exploding smartphone or tablet caused the crash of an Airbus jet operated by EgyptAir three years ago, according to an expert report commissioned by French authorities and seen by AFP on Sunday.
The plane, flying from Paris Charles de Gaulle airport to Cairo, crashed over the Mediterranean between Crete and the northern coast of Egypt on May 19, 2016 killing all 66 people on board.
The aftermath of the crash has been marked by tension, with the Egyptian authorities pointing to a terror attack as the likely cause but their French counterparts insisting on technical issues.
Paris investigating magistrates ordered separate expert reports on two subjects, the first looking at the maintenance of the plane and the second specifically at the phone issue.
There had been speculation that a thermal runaway — a drastic change in temperature — in batteries in an iPhone or iPad in the cockpit could have been the cause of a fire that brought down the plane.
But in the expert report, first reported by the Le Parisien daily and now seen by AFP, three experts said that this was improbable.
"If a spontaneous thermal runaway in a device with a lithium-ion battery can never be completely excluded, the analysis shows that for these devices such an event must be considered extremely improbable," said the report.
It said that this conclusion was only valid if there had been no "external mechanical aggression" on the devices.
The report said there should have been no security impact even if the devices had been charging in the cockpit.
The report on the security of the plane, which was made known in April, said the aircraft should never have taken off because of a series of technical issues on previous flights.
All passengers and crew on board, including 40 Egyptians and 15 French citizens, lost their lives in the crash of the A320.
In December 2016, Egyptian officials said traces of explosives had been found on the remains of some victims, but French authorities were sceptical, as no organisation had claimed responsibility for any attack.