By Rene Marsh and Don Melvin CNN
(CNN) -- A piece of wreckage from a Boeing 777 -- likely from MH370 -- was found washed ashore over the weekend on the coast of Mozambique, a U.S. official told CNN on Wednesday.
The newly discovered debris is on its way to Malaysia for further examination. The wreckage is a piece of horizontal stabilizer skin, the U.S. official said.
A second aviation source says there is no record of any Boeing 777 missing other than Malaysia Airlines Flight 370, which disappeared on March 8, 2014, with 239 people on board.
But Malaysia Airlines called the identification "speculative."
"It is too speculative at this point for MAS to comment," the airline said, using its initials.
The mystery of what happened to the plane remains unsolved. The search has turned up some aircraft debris, but also false leads.
In September, French investigators confirmed that aircraft debris found on Reunion Island in July was from the missing Malaysia Airlines plane.
Debris found in Thailand in mid-January turned out not to be from MH370.
One of aviation's greatest mysteries
The disappearance of MH370 remains one of aviation's greatest mysteries.
The flight took off from Kuala Lumpur International Airport in Malaysia early in the morning, bound for Beijing.
At 1:19 a.m., as the plane was flying over the South China Sea, Malaysian air traffic controllers radioed the crew to contact controllers in Ho Chi Minh City for the onward flight through Vietnamese airspace.
The crew's acknowledgment of the request was the last thing ever heard from MH370: "Good night Malaysian three-seven-zero."
Shortly afterward, air traffic controllers in Malaysia lost contact with the plane somewhere over the sea between Malaysia and Vietnam.
The aircraft's transponder, which identifies the plane and relays details like altitude and speed to controllers, stopped transmitting. MH370 seemingly disappeared without a trace.
Malaysian authorities revealed later that military radar had tracked the plane as it turned back to the west and flew across the Malaysian Peninsula, up the Strait of Malacca, before flying out of radar range at 2:14 a.m. and vanishing once again.
TM & © 2016 Cable News Network, Inc., a Time Warner Company. All rights reserved.