Plane wreckage washed up on a tiny Indian Ocean island will be sent to France for investigation, as hopes mounted Thursday the mysterious object could unlock the riddle of missing flight MH370.

Several experts were convinced the debris was a flaperon from the wing of a Boeing 777, which if proven meant it almost certainly belonged to the Malaysia Airlines plane whose disappearance 16 months ago sparked one of aviation's greatest mysteries.

The two-metre (six-foot) long piece of wreckage washed up on a rocky beach on the French island of La Reunion, some 4,000 kilometres (2,500 miles) from the area where flight MH370 was thought to have gone down in March last year with 239 people on board.

Aviation expert Xavier Tytelman said he and other specialists had compared the debris to hundreds of photos and plane blueprints, and found only one possible match: the flaperon which is a mobile part on the edge of the wing of a Boeing 777.

Scientists say there are several plausible scenarios in which ocean currents could have carried a piece of debris from the plane to the island.

As Malaysian investigators rushed to the scene, authorities prepared to send the object to France for further examination.

Meanwhile a French military helicopter slowly circled the area above the island where the debris washed up on a rocky beach.

Malaysian Prime Minister Najib Razak said the wreckage found on the French island of La Reunion was "very likely" from a Boeing 777, but it remained to be seen if it indeed came from MH370.

The recovered object is expected to be flown out of Reunion island to France on |Friday for analysis, a judicial source told AFP.

It is likely to be sent to a testing site near the French city of Toulouse on Saturday, a second source close to the inquiry said.

- Emotional rollercoaster -

However as expectations mounted over the find, authorities warned against jumping to conclusions.

"Whatever wreckage is found needs to be further verified before we can further confirm whether it belongs to MH370," said Malaysian Transport Minister Liow Tiong Lai.

Flight MH370 was travelling from Kuala Lumpur to Beijing when it mysteriously turned off course and vanished on March 8 last year.

For relatives of those aboard, torn between wanting closure and believing their loved ones were still somehow alive, the discovery was yet another painful turn on an emotional rollercoaster.

"It has started all over again, staring at the phone constantly for news," said Jacquita Gonzales, wife of Patrick Gomes, the flight's cabin crew supervisor.

Local government officials on La Reunion said France's civil aviation investigating authority BEA has been asked to coordinate an international probe into the origin of the debris.

Najib said authorities would send the object to the southern French city of Toulouse to be examined by the BEA, however French sources close to the investigation said it has not been decided where the debris would be analysed in France.

Further adding to the mystery, a torn fragment of luggage was discovered in the same place as the plane wreckage.

"It is really weird, it gives me the shivers," said Johnny Begue, a member of a beach clean-up crew who discovered the plane debris on Wednesday.

- 'Important development' -

Australia, which has led the search for MH370, said the discovery was an "important development".

"If it is indeed wreckage from MH370, it starts to provide some closure for the families of the people on board," said Australia's Transport and Infrastructure Minister Warren Truss.

Authorities involved in the search at sea, guided by the analysis of signals from the plane that were detected by a satellite, believe it went down in the southern Indian Ocean.

But no confirmed physical evidence has ever been found and Malaysian authorities in January declared that all on board were presumed dead.

While there have been several accidents in the region, such as a South African Airways Boeing 747 that crashed near the island of Mauritius in 1987, killing all 159 people on board, none has involved a Boeing 777.

Tytelman said an identification number on the debris meant it could be rapidly identified.

Valborg Byfield, a scientist at the National Oceanography Centre in Britain, said there were two ocean currents which could have swept the wreckage from the crash site to La Reunion.

"Were the plane to have gone done south of the equator, the debris might have been transported by the South Equatorial Current, which bifurcates as it approaches the African coast, with one stream going south along the eastern coast of Madagascar. This would take it past La Reunion."

Angry next of kin have accused Malaysia's government of incompetence, secrecy, and insensitivity toward relatives, and many have questioned the focus on the Indian Ocean, saying other possibilities were being ignored.

Speculation on the cause of the plane's disappearance has focused primarily on a possible mechanical or structural failure, a hijacking or terror plot, or rogue pilot action.

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