Investigators scrambled Thursday to study plane wreckage that washed up on a tiny Indian Ocean island, fuelling hopes that one of aviation's greatest enigmas could finally be solved:  the mystery of missing flight MH370.

The two-meter (six-foot) long piece of wreckage was found on the French  island of La Reunion, offering up bittersweet hope of closure to the families  of 239 people who disappeared in March last year on the Malaysia Airlines  Boeing 777.

Malaysian Prime Minister Najib Razak said the debris, believed to be a part of a wing, was "very likely to be from a Boeing 777 but we need to verify whether it is from flight MH370."

But as local French air transport police studied the debris and experts from Malaysia headed to the scene, 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," Malaysian Transport Minister Liow Tiong Lai told reporters in New York, saying he hoped for answers "as soon as possible".

Flight MH370 was travelling from Kuala Lumpur to Beijing when it mysteriously turned off its route 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 handphone 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.

"No theory is being ruled out, including that it comes from a Boeing 777," La Reunion officials said.

Najib said authorities would ship the object to the southern French city of Toulouse to be examined by the BEA.

Further adding to the mystery, what appeared to be a piece 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.

Australia, which has led a fruitless 16-month search for MH370 in the southern Indian Ocean, 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 eventually 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.

Excitement over the discovery was tempered by suggestions it could be from planes that went down in the region before, including a South African Airways Boeing 747 that crashed near the island of Mauritius in 1987, killing all 159 people on board.

Malaysia Airlines said it remained "too premature for the airline to speculate (on) the origin of the flaperon", a wing component.

La Reunion lies about 4,000 kilometers (2,500 miles) from the area considered the most likely impact zone, but experts said it could have drifted there.

"From the information that we know about the oceanography and our computer modelling, it is completely consistent with the possible path of the debris originating from the current search area," said Charitha Pattiaratchi, an oceanographer with the University of Western Australia.

 The discovery sparked more emotional turmoil for relatives of those missing.

"I'm hopeful, in another respect, I'm not. I guess while you don't know, you still hope," said Sara Weeks, sister of MH370 passenger Paul Weeks of New Zealand.

"We need to know what happened... at least if it's confirmed as a part of the plane then we can go onto the next stage which is still pretty similar to where we were before -- what happened, where's the rest of the plane and where's my brother."

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.

However, nothing has emerged to substantiate any scenario, sustaining a flow of conspiracy theories, with books, documentaries and a thriving online debate positing a range of possibilities.

These include suggestions that the plane was diverted to Kazakhstan, or commandeered to be used as a "flying bomb" headed for US military installations on the Diego Garcia atoll, and was shot down by the Americans. The United States has dismissed this.

"We have had many false alarms before, but for the sake of the families who have lost loved ones, and suffered such heartbreaking uncertainty, I pray that we will find out the truth so that they may have closure and peace," said Najib. (AFP)