Traces of explosives have been found on the remains of an EgyptAir plane that crashed into the Mediterranean last year killing all 66 on board, it has emerged.

The Airbus A320 plunged into the eastern Mediterranean en route from Paris to Cairo on May 19.

Audio from the flight recorder of the crashed aircraft mentions a fire on board the plane in its final moments and an earlier analysis of the plane's flight data recorder showed there had been smoke in the lavatory and avionics bay

Traces of explosives have been detected on remains of victims of an EgyptAir plane crash last May that killed all 66 people on board, the aviation ministry announced (file picture)

The Airbus A320 plunged into the eastern Mediterranean en route from Paris to Cairo on May 19. Pictured is some of the debris found in the sea after the crash

French investigators have said that they had found trace levels of the explosive material TNT on the plane's debris but were prevented from further examining it. Egyptian officials denied that.

An official investigative committee which made the explosives discovery has referred the case to Egypt's state prosecution, Egypt's aviation ministry added in a statement.

The disaster came just seven months after a Russian passenger plane was blown up over the Sinai Peninsula in an attack claimed by the Islamic State group.

That attack, which killed all 226 people on board in October 2015, led to widespread flight cancellations and dealt a major blow to Egypt's vital tourism sector, already weakened by years of unrest unleashed by the 2011 uprising that toppled Hosni Mubarak.

Egypt has never officially said what caused the downing of the Russian plane. But a local ISIS affiliate said it blew up the aircraft with a bomb smuggled on board, and Russia said the aircraft was likely downed by explosives.

No one has claimed to have brought down Flight 804. The Airbus A320 crashed as it approached Egypt's northern coast before dawn on May 19.

The EgyptAir plane was flying at 37,000 feet and disappeared about 130 nautical miles off the Greek island of Karpathos

An official holds the flight recorder of EgyptAir flight MS804. Aviation experts have said there is little chance that a mechanical fault was responsible

France's accident investigation agency has said that smoke detectors went off during Flight 804's final moments.

Spokesman Sebastien Barthe told The Associated Press earlier this year that such messages 'generally mean the start of a fire.'

Industry publication Aviation Herald has reported that sensors detected smoke in the plane's lavatory, as well as a fault in two of the plane's cockpit windows in the final moments of the flight.

France opened a criminal investigation into the disaster in June.

Egypt's aviation minister, Sherif Fathy, had said a terrorist attack was the most likely cause of the EgyptAir crash.

The chances of an attack were 'higher than the possibility of a technical (failure)' for the downing of the plane, Fathy said in May following the crash.

Aviation experts have said there is little chance that a mechanical fault was responsible.

The plane only entered service in 2003, making it relatively new for an aircraft that tends to operate for 30 to 40 years.

The EgyptAir plane was flying at 37,000 feet and disappeared about 130 nautical miles off the Greek island of Karpathos.

EgyptAir employees and relatives of the victims hold signs and flags during a commemoration march for the 66 victims

No one has claimed to have brought down Flight 804. The Airbus A320 crashed as it approached Egypt's northern coast before dawn on May 19. A ship is pictured searching for wreckage on the day of the crash

The plane plunged 22,000 feet and swerved sharply before it disappeared from radar screens, Greece's Defence Minister Panos Kammenos said at the time.

If a bombing is established, investigators will have to determine if a device could have been smuggled aboard a flight taking off from France's busiest airport, Paris Charles de Gaulle.

Security has been tight since last year's jihadist attacks in the French capital.

Internet site FlightRadar24 indicates the EgyptAir plane travelled to Egypt, Tunisia and Eritrea in the two days before Thursday's crash, leaving open the possibility that a device could have been planted prior to its arrival in France.

ISIS has carried out several attacks in recent years, mainly in the Sinai, where it is based, but also on the Egyptian mainland.

The group claimed responsibility for a suicide bombing at a Cairo church on Sunday, which killed at least 24 people, mainly women, and wounded nearly 50.

In recent months Egypt has spent millions of dollars trying to restore international confidence in its airport security measures.