A mystery that began with the disappearance of a Malaysian plane en route to China that detoured to the waters off Australia’s coast has now spread across the Indian Ocean close to Africa. Next stop: France.

An aircraft part found on a French island is headed for a government laboratory in Toulouse, said a U.S. official who wasn't authorized to speak about the investigation. It will be examined by Wednesday, according to the Paris prosecutor’s office.

A suitcase found near the debris on Reunion island also will be studied, according to an e-mailed statement from the prosecutor, which said a French judge handling the inquiry into the airplane parts will meet with Malaysian officials on Aug 3.

The involvement of investigators and officials from multiple countries underscores the complexity of the case.

“It’s a bit difficult when something lands in the great white oceans, because you don’t own the ocean more than 12 miles off your coastline,” Brian O’Keefe, a former vice president of the International Civil Aviation Organization’s general assembly, said by phone from Canberra, Australia. “It’s an unusual case where the wreckage is found in a different jurisdiction to the place where the accident is thought to have happened.”


Treaty governs

How the investigation will be conducted and who is in charge -- formulations that occasionally lead to international tensions and intrigue -- are governed by an ICAO treaty.

Under that treaty, overseen by the arm of the United Nations, investigations are normally led by the country where a crash occurred. If it’s outside the boundaries of any nation, control reverts back to the country where the aircraft was registered. That would be Malaysia if the part turns out to be from Malaysia Airlines Flight 370, missing since March 8, 2014, with 239 people on board.

The treaty also gives the U.S. National Transportation Safety Board the legal right to participate in the Flight 370 investigation because the 777 aircraft was manufactured in the U.S. Boeing Co. would also participate as an adviser to the NTSB.

While nations sometimes squabble over who oversees an accident probe and some countries don’t have established investigation boards, the world’s aviation safety agencies have done a good job of setting politics aside, said Kenneth Quinn, a Washington lawyer who has also served on ICAO committees.


Pool resources

“The process works extraordinarily well when it involves an accident investigation,” Quinn said. “There is an increasing global cooperation to pool resources and apply expertise to find out what went wrong and why.”

If a crash was intentional, as may be possible with the missing Malaysia flight, the politics become more complex, he said. “When it’s an act of sabotage, when it’s a purposeful or willful act, then it can become a difficult, painful exercise for authorities,” he said.

After EgyptAir Flight 990 went down off the coast of Massachusetts on Oct. 31, 1999, killing all 217 people aboard, Egyptian authorities turned responsibility for the investigation over to the NTSB. That created tensions when the NTSB later concluded that a pilot had intentionally crashed the Boeing 767.

Similar tensions have hung over the investigation of Malaysia Airlines Flight 17, which was shot down by a missile over Ukraine on July 17, 2014, killing 295. Russian-backed rebels were fighting the Ukraine government in the area. The Ukraine government turned over the investigation to the Dutch.


Fresh momentum

If the latest investigation shows the piece is from Flight 370, which vanished on its way from Kuala Lumpur to Beijing, it won’t pinpoint the plane’s resting place. It would, though, give fresh momentum to search efforts off the west coast of Australia that so far have failed to find any debris from the doomed flight.

“The sighting of this wreckage is consistent with the aircraft being located in the search area,” Australia’s Deputy Prime Minister Warren Truss told a media conference in Canberra Friday. Investigators have been focusing on a remote stretch of ocean some 3,800 kilometers (2,360 miles) southeast of Reunion.

“It’s only a small part of the aircraft, but it could be a very important bit of evidence,” Truss said. “Assuming it is eventually identified as wreckage from MH370, what this does is eliminate some of the theories that have been around.”


Other theories

Some amateur sleuths have argued that the plane was hijacked and landed in central Asia; that it was seen flying over the Maldives due south of India; or that it was shot down close to Diego Garcia, a U.S. naval base south of the Maldives.

Additional evidence may be gleaned from the arthropods clinging to the debris. Barnacles, dozens of which can be seen in photos of the part, are sometimes capable of providing scientists a road map of where whales or boats have traveled, said William Newman, an emeritus professor at the Scripps Institution of Oceanography in La Jolla, California.

A part number on the wing component confirms it was from a 777, the same model as MH370, according to a U.S. official, who wasn’t authorized to speak about the investigation.

While investigators haven’t definitively determined that the piece came from MH370, “it probably is from the plane,” O’Keefe said. “There’s no record of anybody else reporting a piece falling off an airplane in this area.”


Ocean crashes

Malaysia Airlines identified the part as a flaperon, a movable panel on the rear of the wing that’s used to bank the plane and can also be moved to expand the wing’s size during takeoff and landing. Other than MH370, no 777s are known to have crashed in the Indian Ocean.

The tattered remains of a suitcase also were found on a Reunion island beach near where the wing part was discovered, according to a report by the Journal de L’ile de La Reunion.

Airline representatives will meet with passengers’ families in Beijing on Aug. 7 to discuss issues related to MH370, according to a note it sent to families Friday.

There was conflicting information on when the examination of the wreckage would begin. The U.S. official said it was to start Tuesday, while French prosecutors said it would begin Wednesday.

Flight 370 went missing after communication equipment on the aircraft stopped functioning and it veered from its course and flew over the Indian Ocean. Investigators have concluded that someone on board intentionally disabled tracking devices.

Based on pings between a satellite and the plane, searchers believe it flew until it ran out of fuel somewhere along an arc west of Australia in the Indian Ocean.

Searchers have found no trace of the plane despite deep-sea sonar scans of tens of thousands of square kilometers.