A dual Australian citizen was on EgyptAir flight MS804 that is believed to have crashed with 66 people on board.
The Airbus A320 disappeared from radar over the Mediterranean Sea while travelling from Paris to Cairo.
The Federal Government Friday morning confirmed one of the passengers was an Australian-UK dual national.
Foreign Minister Julie Bishop made the following statement:
We are working closely with UK authorities, which are taking the lead in the provision of consular assistance to the man's family.
The Government is working with our partners and allies to understand the reasons behind the flight's disappearance and presumed crash.
It is too early to speculate on the cause of this incident.
My thoughts are with the families and friends of those affected.
British news outlets have named the only Briton onboard as Richard Osman but it is not immediately clear whether he had any connection to Australia.
Debris not believed to be linked to EgyptAir flight
Confusion surrounds whether the remains of the flight has been found, with the airline initially suggesting debris near Greece could be linked to the downed plane.
Airline officials initially said search teams found wreckage near the Greek island of Karpathos. However EgyptAir later revised the statement and Greek officials said debris recovered so far was not from the plane.
Egyptian ship captain Tahrek Wahba posted an image of debris on Facebook. It was not immediately apparent where the image was captured.
EgyptAir crash an accident, or act of terrorism?
French President Francois Hollande said "no hypothesis" should be ruled out, including terrorism.
"The information we have gathered -- ministers, members of government and, of course, the Egyptian authorities -- confirm, sadly, that it has crashed. It is lost," Hollande told reporters at a press conference in Paris on Thursday night (AEST time).
The French President offered "solidarity" to the families of passengers offering support to the Greek and Egyptian authorities searching for debris.
"We have to send them ships and planes to find where the plane crashed, and to do whatever we can to collect the debris. That will allow us to find the truth," Hollande said.
Paris prosecutors also announced an investigation into the crash.
Egyptian Aviation Minister Sherif Fathy has said that the crash "could be a terrorist act", while also urging the community not to jump to conclusions.
"Let us stop speculations," he said at a press conference on Thursday night (AEST).
"Let us talk about the precise procedure -- which is where the plane is and whether we will find the plane or find the debris.
"Afterwards, we will carry out our work so we can reach the causes behind it. It doesn't mean that we can deny that it could be a terrorist act or a technical act."
Passengers included one child, two babies
The airline reported flight MS804 missing on Thursday afternoon (AEST time), after the aircraft disappeared from radar 10 miles inside Egyptian airspace, over the Mediterranean Sea.
Among the 56 passengers were 15 French, 30 Egyptians, two Iraqis and one each from Canada, Belgium, Kuwait, Saudi Arabia, Sudan, Chad, Portugal and Algeria as well as a British-Australian dual citizen. Three children are also confirmed on board.
There are also three security personal and seven crew members on the aircraft. One child and two babies are among the passengers.
EgyptAir flight 'just vanished'
The New York Times have quoted the head of Egypt's air navigation authority, Ehab Mohy el-Deen, who said Egypt air traffic controllers were notified by their Greek counterparts who lost contact with the plane.
"They did not radio for help or lose altitude. They just vanished," he said.
Greek defence ministry authorities are also investigating an account from a merchant ship captain claiming to see a 'flame in the sky', according to Reuters.
A Greek defense ministry source said authorities were also investigating an account from the captain of a merchant ship who reported a 'flame in the sky' some 130 nautical miles south of the island of Karpathos.
The Egyptian military denies receiving a distress signal from an emergency locator transmitter or beacon at 4:26am, after a previous statement from EgyptAir.
The time the distress signal was received is two hours after last radar contact was made.
Global flight tracking service Flightradar24 showed the plane's signal disappeared over the Mediterranean Sea about 2.45am Cairo time.
An EgyptAir statement on Thursday afternoon said the Airbus A320 disappeared while travelling at 37,000 feet.
The pilot has more than 8000 hours, including more than 2000 hours on the Airbus 320. The co-pilot has more than 2000 hours experience, according to EgyptAir.
The aircaft, which was manufactured in 2003, reportedly left from Charles De Gaulle Airport in Paris about 11pm on Wednesday night (local time).
Central Queensland University Head of Program for Aviation, Ron Bishop, told HuffPost Australia there was nothing unusual about the flight's path.
"The maximum altitude for the Airbus A320 is 40,000 feet and anywhere under 39,000 feet is good so their altitude sounds normal," Bishop said.
"It seemed to be cruising normally until it dropped off the radar."
EgyptAir is hosting the passengers' families near Cairo Airport, providing doctors and translators.
For anyone concerned about a loved one, contact either of the below toll-free numbers provided by EgyptAir.
Outside Egypt or on a mobile: +20225989320
Within Egypt: 080077770000