Investigators in Malaysia, Australia and the United States have seen photographs of the latest object, and sources say there is a good chance it comes from a Boeing 777.
The object has the words "NO STEP" on it and could be from the plane's horizontal stabilizer — the wing-like parts attached to the tail, sources say. It was discovered by an American who has been blogging about the search for MH370.
Australia's Joint Agency Coordination Center said it was aware of the discovery and arranging for a thorough examination. Malaysia Airlines said it was "too speculative at this point" to comment.
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Malaysian Transport Minister Liow Tiong Lai said on Twitter that there was a "high possibility debris found in Mozambique belongs to" a Boeing 777, but he said that was "yet to be confirmed and verified."
I urged everyone to avoid undue speculation as we are not able to conclude that the debris belongs to #mh370 at this time. (3/3)
Darren Chester, Australia's minister for infrastructure and transport, said in a statement Thursday that the location was consistent with drift modeling related to the search. The discovery "reaffirms the search area for MH370 in the southern Indian Ocean," he said.
Boeing engineers are looking at the photos, according to sources. The company has declined to comment.
The development comes days ahead of the second anniversary of the jet's disappearance en route from Kuala Lumpur to Beijing on March 8, 2014, with 239 people on board.
Almost three-quarters of an internationally set 46,000-square-mile search zone has been covered so far in the hunt for the missing airliner — an area of ocean floor larger than the state of South Carolina.
The operation is due to be completed by the middle of this year. The Joint Agency Coordination Center says that if no "credible new information" about the jet's location emerges, the search will end.
The Cry for Truth, an association of families of the plane's passengers and crew, objected to plans to end the search, saying in a strongly worded statement that its members feared that organizers were trying to run out the clock.
"With no word from anyone about the investigations over the last year, we wonder if the authorities hope that if they stop updating us we will eventually stop asking and this will lead to an uneventful end to any serious ongoing inquiry," the group said.
"It appears that the concerned parties — Malaysia, Australia and China — are preparing to bring the curtains down on the search for MH370," the statement said. "We believe that this would be truly unfortunate.
"The organization announced a remembrance program scheduled for Sunday in Publika Square in Kuala Lumpur.
Tom Costello is an NBC News correspondent based in Washington, D.C.
Alastair Jamieson is a London-based reporter, editor and homepage producer for NBC News.