He told Europe 1 radio station in Paris: “A technical problem, a fire or a failed motor do not cause an instant accident, and the team has time to react.
“The team said nothing, they did not react, so it was very probably a brutal event and we can certainly think about an attack.”
Confusion over whether there was a distress call or not has fuelled concerns the plane’s disappearance may have been caused by an explosive device.
EgyptAir initially said it had received no distress call but later said it had. Egypt’s Civil Aviation Authority said the military had received a call two hours after the plane dropped off radar, but its latest line said it did not.
Retired British Airways pilot, Alistair Rosenschein, told Sky News, a hijacking cannot be ruled out because of the lack of radio contact from the pilot.
Air travel expert Julian Bray said no alert being made could mean the airliner suffered a “catastrophic failure” possibly as a result of an explosion.
He said: “It has to be a catastrophic failure because everything went dead and they wouldn’t have had time to get a message out.
“It’s gone into the deepest part of the Mediterranean.”
Will Geddes, managing director of private security firm International Corporate Protection, urged people to be “cautious” about assuming the disappearance was caused by terrorism because the flight had departed from Paris, which has suffered several attacks in recent years.
He said: ”There’s a lot of concentrated focus on terrorist issues around Paris but one has to be cautious about drawing conclusions.”
But Mr Geddes added that even if it is confirmed the plane did give an emergency signal, that would not rule out terrorism as a possibility because an explosion would not necessarily have caused the immediate destruction of the plane.
He added: ”It would not have needed to be a large device – if it was a terrorist-related failure – to lose cabin pressure.”