French authorities investigating the EgyptAir crash that killed 66 people are said to be looking into whether the plane was brought down by an overheating phone battery. According to Le Parisien, a source within the investigation told the French newspaper that the fire in the cockpit of the Airbus A320 may have started where the co-pilot stowed his iPad and iPhone 6S.

EgyptAir flight MS804 was travelling from Paris to Cairo when it disappeared from radar on 19 May 2016. Egyptian investigators have speculated that the crash, which killed all 56 passengers, seven crew members and three security personnel on board, was caused by an act of terrorism due to traces of explosives reported to be found on some the victims.

Investigators in France have disputed these claims, saying that data recorded from the aircraft around the time it disappeared points to an accidental fire on the right-hand side of the flight deck, next to the co-pilot.

According to The Times, CCTV pulled from cameras at Paris' Charles de Gaulle airport show that the co-pilot stored a number of personal items above the instrument panel, near to where the first signs of trouble were detected.

An automated alert indicated a series of malfunctions on the right-hand flight deck window, followed by smoke alerts going off in a toilet and in the avionics area below the cockpit, minutes before the plane vanished.

'A troubling parallel'

A source from the investigation told Le Parisien that they were investigating links between where the co-pilot placed his items and the spot where the fire started. "The images show very clearly that the Egyptian co-pilot placed his telephone, tablet and bottles of perfume bought before boarding on the glare-shield," the newspaper said.

"The investigators thus note a troubling parallel between the placing of these items that are fed by lithium batteries and the triggering of alarms during the flight."

It is understood that the information provided by the Le Parisien source has not been independently verified. While investigators may have at one point probed whether an overheating mobile device started the fire, this line of inquiry has not been advanced.

An Apple spokesperson said: "We haven't been contacted by GTA or any authority investigating this tragic event. We have not seen the report but we understand there is no evidence to link this event to Apple products. If investigators have questions for us, we would of course assist in any way we can. We rigorously test our products to ensure they meet or exceed international safety standards."

Smartphones containing lithium-ion batteries have been known to explode when exposed to excessive heat or pressure. Samsung was forced to recall its Galaxy Note 7 last year due to widespread reports of the handset catching fire, caused by stressed batteries. This led to a number of airlines banning the phone from flights.