(CNN) A piece of plane debris found off the coast of Mozambique has renewed hope of solving the mystery of the missing Malaysia Airlines Flight 370.

A U.S. official said it was likely the wreckage came from a Boeing 777 like MH370, while Malaysian Transport Minister Liow Tiong Lai said there was a "high possibility" the part came from that type of plane. Malaysia Airlines Flight 370 is the only 777 to be missing in the region where the piece was found.

Others are being more skeptical. Cmdr. Joao Abreu, the chief executive of the Mozambique Civil Aviation Authority, told CNN's David McKenzie that the piece of debris might belong to a "medium-sized plane" and not a 777. Abreu noted that there is no marine life of any kind or major wear and tear on the piece, as would be expected after nearly two years in the ocean. Still, he is not ruling anything out until the piece is analyzed further.

In early March 2014, Flight 370 took off from Kuala Lumpur, Malaysia, en route to Beijing with 227 passengers and 12 crew members on board. It vanished from radar in airspace over the Gulf of Thailand.

After so many false alarms and theories for the disappearance of the plane, family members of the victims are treating this new report with a great deal of suspicion, and even anger.

"Just like previous cases of suspected debris, I always think that we need to wait for various authorities to verify, confirm (what the item actually is) and to show us concrete evidence," Steve Wang, whose mother was one of the 239 passengers aboard the flight, told CNN.

"(The debris is) all so scattered to such a wide span of areas, it is hard to see how one piece can really help," he said.

Zhang Meiling, who lost three family members, had stronger words: "We don't believe in the stories of debris anymore."

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) — Liow Tiong Lai (@liowtionglai) March 2, 2016

What did they find?

The piece of debris suspected to be from MH370.

The wreckage is a piece of horizontal stabilizer skin, the U.S. official said, the part of the aircraft's tail that stays horizontal as the plane flies.

It measures about 35 inches by 22 inches (89 centimeters by 56 centimeters) and is apparently from a Boeing 777, like the missing MH370 airliner.

The debris includes a fastener, which an executive at fastener company LISI Aerospace said is a pretty standard part.

"I would expect to see this on many varieties of Boeing aircraft, not particular to a 777," said Jared Young, vice president of research and development.

An aviation source said there was no record of any Boeing 777 missing other than Malaysia Airlines Flight 370.

Who found it?

JUST WATCHED Likely piece of missing MH370 airliner found Replay More Videos ... MUST WATCH Likely piece of missing MH370 airliner found 04:37

American Blaine Gibson had chartered a boat for a weekend trip off the coast of Mozambique and found the plane part washed ashore on a sandbar after the boat's captain spotted it.

He is also part of an independent group that interpreted data in a bid to find the missing plane.

"What went through my mind when I found it is that this is something that could be part of an airplane and could be part of that airplane," Gibson told CNN.

"Anything that can help lead to the truth of what happened and get the families the answers that they long for and deserve no matter what they are, whatever the truth is, anything that leads to that, is very good and needs to be done," he said.

It's not unusual for private people and companies to get involved in searches for missing planes, especially when the search has gone on for a long time.

After the underwater search for MH370 was postponed, Australia said it would negotiate with private contractors to conduct the next phase. Authorities chose the Dutch firm Fugro Survey to carry out the Indian Ocean search.

'Violent breakdown'?

JUST WATCHED Possible MH370 debris moved for further examination Replay More Videos ... MUST WATCH Possible MH370 debris moved for further examination 01:54

The discovery was reported to officials Monday, and Gibson handed over his find to Mozambique authorities. The piece will be sent to Australia for examination.

While it took more than a month for French investigators to confirm that debris found on Reunion Island last July was from the missing plane, Geoffrey Thomas, managing director of Airline Ratings, said confirmation should take just a few days.

Thomas added that the debris was found "in the right area" -- a location consistent with modeling done by the University of Western Australia that suggests the plane went down over the southern Indian Ocean.

If confirmed, it suggests a violent breakdown and discounts a theory that a rogue pilot gently took the plane into the water to mask his intentions of crashing it, Thomas said.

Two-year wait for answers

The discovery comes just days before the second anniversary of the disappearance of the flight, which took off on March 8, 2014.

The two-year mark carries extra significance because it's the last day for families to file for airline compensation.

Under international treaties, families have to make a claim against the airline within two years. But for them to do that, they would have to admit that their loved ones are dead, which many are unwilling to do.

Photos: Remembering the passengers of MH370 Photos: Remembering the passengers of MH370 There is still no way to know for sure why Flight MH370 ended, but we are learning more about the lives of those on board. CNN is remembering them through snapshots shared with us. Hide Caption 1 of 12 Photos: Remembering the passengers of MH370 Rodney and Mary Burrows were looking forward to becoming first-time grandparents after their return home to Australia. Hide Caption 2 of 12 Photos: Remembering the passengers of MH370 Australians Catherine and Robert Lawton were traveling with friends on vacation when the flight disappeared. Hide Caption 3 of 12 Photos: Remembering the passengers of MH370 Paul Weeks was traveling to Mongolia for a new job as an engineer. His wife says Paul left behind his watch and his wedding ring before the trip, in case anything happened to him while he was away. Anderson spoke with Paul's brother & sister who said they are coping by spending time together as a family. Hide Caption 4 of 12 Photos: Remembering the passengers of MH370 Chandrika Sharma, left, was on Flight 370; her daughter Meghna and husband K.S. Narendran wait patiently, trying to manage their anxiety and longing for her return. Hide Caption 5 of 12 Photos: Remembering the passengers of MH370 Muktesh Mukherjee and Xiaomo Bai had been vacationing in Vietnam and were on their way home to their two young sons in Beijing. Hide Caption 6 of 12 Photos: Remembering the passengers of MH370 76-year-old Liu Rusheng, an accomplished calligrapher and one of the oldest passengers on the flight, was in Malaysia to attend an art exhibition with his wife. Hide Caption 7 of 12 Photos: Remembering the passengers of MH370 Teens Hadrien Wattrelos and Zhao Yan are shown in a photo on Wattrelos' Facebook page. The photo is captioned, simply, "I love you," in French. Hide Caption 8 of 12 Photos: Remembering the passengers of MH370 Firman Chandra Siregar, 24, studied electrical engineering in Indonesia and was on his way to Beijing on board Flight 370 to start a new job at an oil company. Hide Caption 9 of 12 Photos: Remembering the passengers of MH370 Patrick Francis Gomes, center, was the in-flight supervisor for the missing plane. His daughter describes him as a quiet person with a sense of humor. Hide Caption 10 of 12 Photos: Remembering the passengers of MH370 Ch'ng Mei Ling, a Malaysian citizen who lives in Pennsylvania, is a process engineer at a chemical company. Hide Caption 11 of 12 Photos: Remembering the passengers of MH370 We do not have photos of all 239 passengers, but we wanted to remember that there are loved ones around the world missing them right now. View CNN's complete coverage of Flight 370. Hide Caption 12 of 12

"We have not picked up any compensation, we simply want our man back!" said Ye Lun, whose brother-in-law was a passenger.

Voice 370, a family support group, said an event would be held Sunday at The Square in Publika, Kuala Lumpur, Malaysia.

"The families and friends of passengers on board MH370 have endured a long wait of two years for reliable news on the whereabouts of MH370 and the fate of our loved ones on board," the group said, calling for funds and for the search to continue.