Data recovered from one of the black boxes from the EgyptAir plane that crashed last month showed smoke alarms had sounded on board, while soot was found on the wreckage, an Egyptian-led investigative committee has said.

Flight MS804 was en route from Paris to Cairo when it crashed in the Mediterranean Sea on May 19, killing all 66 people on board.

"Recorded data is showing a consistency with ACARS messages of lavatory smoke and avionics smoke," the committee said on Wednesday.

Investigators had previously announced that the plane's automated Aircraft Communications Addressing and Reporting System (ACARS) sent signals indicating smoke alarms on board the plane before it went down.

"Parts of the front section of the aircraft showed signs of high-temperature damage and soot," the committee statement added.

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Egyptian investigators had said that the plane turned 90 degrees left, then a full 360 degrees to the right, plummeting from 38,000ft to 15,000ft before disappearing at about 10,000ft.

The aircraft had been cruising normally in clear skies on an overnight flight when it crashed.

The aircraft's flight data recorder, along with the second component of the black box containing sound recordings from the cockpit, was found two weeks ago.

The device had been found broken into several parts and suffered serious damage, but salvage experts managed to retrieve the recorder's memory unit, Egypt's civil aviation ministry had said.

The committee statement said the search remained for the remains of the passengers and crew.

It "will continue till the full recovery of all the remains at the crash location," it said.

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Overall, 40 Egyptians, 15 French, two Iraqis, two Canadians and one person from each of Algeria, Belgium, Britain, Chad, Portugal, Saudi Arabia and Sudan were on board the Airbus A320.

Both Egyptian and French judiciary have opened investigations into the mysterious incident, without ruling out that it had been deliberately downed.

The crash followed the bombing of a Russian passenger over Egypt's restive Sinai Peninsula last October, killing all 224 passengers and crew.

The Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group has claimed responsibility for that attack, but there has been no such claim linked to the EgyptAir crash. The group has usually been quick to claim responsibility for large-scale attacks.

Egypt's aviation minister had initially said an attack was the more likely explanation, but President Abdel Fattah el-Sisi said there was no theory being favoured yet.