Teams are studying images of three pieces of debris to see if they belong to the ill-fated Malaysia Airlines flight. Two were found in Madagascar, with the other discovered thousands of miles away, off Australia.
Officials said on Friday they were examining a possible plane part found among driftwood and seaweed on Kangaroo Island, off the coast of Australia.
Australian authorities said they were also examining images of two other pieces of debris that were found in Madagascar.
The Australian Transport Safety Bureau said it was looking at images of all three items and would need to study them further before reaching any conclusion.
"We have seen the photos and governments are being consulted on how best to have that examined," bureau spokesman Dan O'Malley said.
Australian Transport Minister Darren Chester said in a statement that all three items would be investigated in connection with the plane's March 2014 disappearance.
Beachcomber's chance discovery
The fragment of white wreckage found on Kangaroo Island was said to resemble part of a plane, with the words "Caution No Step," and a honeycomb symbol. However, the Australian broadcaster Channel Seven said the part, accidentally discovered by a beachcomber, may also have come from a Cessna that crashed off the island's coast in 2002.
Officials said the two parts found off the coast of Madagascar were found by self-funded US adventurer Blaine Gibson, who has been conducting his own independent hunt for clues about the fate of the plane.
One piece of debris, found on the island of Nosy Boraha, was said to resemble part of a plane seat, while the other appeared to some from the cover panel of a plane wing.
In February, Blaine found debris off the coast of Mozambique, which experts determined must have come from the missing Boeing 777.
Few clues so far from debris
So far eight pieces of wreckage, excluding the most recent finds, have been discovered on coastlines along the western Indian Ocean - thousands of kilometers from the main search zone off Western Australia.
Officials have so far had no success in finding the main part of the wreckage, with crews expected to complete a sweep of the 120,000-square kilometer (46,000-square mile) area by August.
The plane took off from Kuala Lumpur bound for Beijing, carrying 239 passengers and crew, but disappeared shortly afterwards.
Investigators believe the plane's transponder, which would have given a clue about its whereabouts, may have been deliberately switched off.
The search of more than two years is then due to come to an end, although families of the missing passengers have called for the hunt to be extended.
rc/sms (AFP, AP, Reuters)