Australian investigators, relatives of passengers query what happened to MH370 after confirmation of debris

Australian authorities have confirmed the plane wing debris found on the French island of Reunion in the Indian Ocean has been confirmed to be from missing Malaysian Airlines flight MH370.

Australian Prime Minister Tony Abbott said on Thursday the finding confirmed that the Australian-led search for the missing Boeing-777 was in the correct area.

"The fact that this wreckage does very much look like it's from MH370 does seem ... very consistent with the search pattern we've been using," he said.

Malaysian Prime Minister Najib Razak said in Kuala Lumpur overnight that the debris found on Reunion Island was in fact from missing flight MH370.

"Today, 515 days since the plane disappeared, it is with a very heavy heart that I must tell you that an international team of experts has conclusively confirmed that the aircraft debris found on Reunion Island is indeed from MH370," Najib told reporters.

Australian aviation experts hoped barnacles and shells on the debris could help pinpoint the rest of the plane, which appeared to be on the ocean floor.

However Monash University ocean expert Greg Bamber said identifying the wing offered little help to finding the rest of the plane's wreckage.

"The Indian Ocean is a very large ocean; it's unexplored, it's deep," Bamber told Australia's Nine Network.

"It's not only the currents, it's the winds, the waves and depending on the size of the debris, whether it's above the water or below," he added. "It's more difficult than finding a needle in a haystack, because the haystack is huge and it's moving all the time."

Next-of-kin, investigators, and the aviation industry are still left with the vexing question of what caused the Boeing 777 aircraft to inexplicably divert on a flight from Kuala Lumpur to Beijing on March 8, 2014.

"Today, while it is sad, it is also very good news for us and the families I'm sure I'm speaking on behalf of," Australian Jeanette Maguire - who had two relatives on the ill-fated flight - told the Nine Network.

"It's still raw mixed emotions in there, but it's a relief," she said. "It's part of a puzzle we needed, we needed to find where this plane had landed and ended up, so to have a little bit of information has been very rewarding."

George Burrows, father of Australian Rodney Burrows who was on MH370, told Australia's national broadcaster the family was back to square one with the confirmed discovery of a part from the missing flight.

Burrows said he hoped to get more answers after the Malaysian government.

"We were getting over things ... and then this happens and (we are) back to square one," Burrows told ABC radio. Endi