According to French specialists' conclusions included in documents released on Wednesday
An EgyptAir disaster in 2016 in the Mediterranean that killed 66 people was likely caused by a fire that originated in the cockpit.
A leak from the co-oxygen pilot's mask and the burning of a cigarette smoked by the pilot or co-pilot were the causes of these incidents.
Initially, Egypt's aviation minister claimed that a terrorist attack, not a lack of maintenance, was more likely to have brought the plane down.
The jet crash was investigated as a manslaughter case once terrorism was ruled out.