Experts in France are due to begin examining part of a wing that washed up on the island of Reunion, to see if it came from Flight MH370.
The fragment, known as a flaperon, is from a Boeing 777, the same make as the missing Malaysian airliner.
France has invited Malaysian and Australian aviation experts to Toulouse to help with the investigation.
Australia’s Deputy PM Warren Truss said the teams may be able to say this week if it came from the plane.
For reasons that remain unclear the Malaysia Airlines plane, with 239 people on board, veered off course on its way from Kuala Lumpur to Beijing in March 2014.
It is believed to have crashed into the sea, though no confirmed trace has ever been found despite a massive search operation.
The examination of the wing part will start early on Wednesday afternoon, AFP news agency reported.
Attending will be French and Malaysian experts, Boeing employees and representatives from China – the country that lost most passengers in the disaster.
Jean-Paul Troadec, the former head of the French BEA agency that investigates air accidents, was quoted by AFP as saying that the examination would concentrate on two issues – whether the wing part belongs to MH370 and if so, whether it could then provide any information on the final moments of the plane.
Mr Troadec said paint on the wing part – which has already been confirmed as coming from a Boeing 777 plane – was a vital part of the investigation.
“Every airline paints their planes in a certain way… and if the paint used is used by Malaysia Airlines and other companies, there may be more certainty,” he said.
No other Boeing 777s are thought to have crashed in the region.