A dual Australian-British citizen has been confirmed to have been on board.

Richard Osman, 40, was travelling on Flight MS804 from Paris to Cairo, where he worked as an executive with mining company Centamin, when the plane disappeared between the Greek island of Crete and Egypt's coastline on Thursday.

The geologist and new father who had previously worked in a West Australian gold mine has been identified as a passenger on board the missing EgyptAir flight that abruptly swerved before vanishing from radar.

Just two weeks ago, Mr Osman and his wife, Aureilie, had welcomed the birth of their second daughter, Olympe, a sister for one-year-old Victios. Welsh-born Mr Osman was said to be "deliriously happy" at becoming a father again, his brother Alistair told the South Wales Evening Post.

"Richard was so happy at the birth of his second daughter, and yet two weeks later he is no longer with us. It's an absolute tragedy," Alistair Osman said. "He was really happy about having the baby and was looking forward to enjoying a lovely family life with his two girls."

Australian Foreign Affairs Minister Julie Bishop confirmed an Australian-British dual national was on board the missing flight.

Contact with the flight was lost 10 miles after entering Egyptian air space and 20 minutes from its destination. The flight plummeted from its cruising altitude, veering right and left and disappeared from radar screens at 10,000 feet.

The loss of the flight, EgyptAir 804, was the second civilian aviation disaster for Egypt in the past year. It immediately resurrected fears and speculation about the safety and security of Egyptian air travel and broader questions about terrorism against civilian air travel.

Sherif Fathy​, Egypt's aviation minister, told the London Telegraph it was more likely the Airbus was brought down by terrorist attack than a technical breakdown.

"If you analyse the situation properly, the possibility of having a terror attack is higher than the possibility of having a technical fault," he said.

In the US, both the Democrat and Republican presidential frontrunners cited terrorism as the likely cause.

"A plane got blown out of the sky," Republican Donald Trump told a fundraiser in New Jersey. "And if anybody thinks it wasn't blown out of the sky, you are 100 per cent wrong, folks. OK? You're 100 per cent wrong."

US Democratic presidential frontrunner Hillary Clinton also cited terrorism.

"It does appear that it was an act of terrorism," Mrs Clinton said on CNN.

However, US officials said government satellites could not find any indication of an explosion – such as a heat signature – on MS804's  flight path, the Telegraph reported.

As distraught families continued to wait for news, details emerged of victims, including a student at France's elite Saint-Cyr military academy who was going home to Chad to mourn his mother. An official at Chad's embassy in Paris said he was "was going to give condolences to his family".

CNN identified the pilots of the plane as captain Mohamed Said Shoukair​ and first officer Mohamed Mamdouh Ahmed Assem​, citing an official close to the investigation and a security source.

The head flight attendant was identified as Mirvat Zaharia Zaki Mohamed.

Authorities in Egypt and France said it was too soon to say what caused the Airbus A320 carrying 66 people to come down on its way from Paris to Cairo.

John Goglia​, a former US National Transportation Safety Board member, told AP that early indications point more to a bomb than to a structural or mechanical failure.

Mr Goglia told the news agency that "given the fact that [the pilot] made those abrupt turns without broadcasting any maydays would indicate to me that something catastrophic like a device happened".

A mechanical failure "still has to be considered but at this point I would put that down pretty low" he said.

In the 24 hours before it disappeared, the plane, registration SU-GCC, had carried out three other trips: a return trip from Cairo to Tunis, and then the flight from Cairo to Paris.

EgyptAir said there were 66 people on board the flight, including a child and two babies.

Those on board, according to EgyptAir, included 15 French passengers, 30 Egyptians, two Iraqis, one Briton, one Kuwaiti, one Saudi, one Sudanese, one Chadian, one Portuguese, one Belgian, one Algerian and one Canadian.

Egyptian officials issued conflicting information about whether wreckage had been found, correcting earlier claims that wreckage had been found, saying that debris near a Greek island "did not come from the plane".

- London Telegraph, wires