Update as of 4:30 a.m. EDT: Families of Chinese passengers of Malaysia Airlines Flight MH370 have demanded a quick confirmation of whether the debris found on the island of Réunion in the Indian Ocean is from the missing Boeing 777-200.

"We don't want to hear an official giving 99 per cent guarantee. We want 100 per cent confirmation!" the next-of-kin said, in a statement posted on social media Thursday afternoon. "No matter where the wreckage is, what we are most concerned is the whereabouts of our loved ones.”

French authorities said Thursday that no hypothesis could be ruled out in the investigation into the debris, but its origin is yet to be identified. A Malaysian official said, earlier on Thursday, that it was “almost certain” that the debris was from a Boeing 777.

Meanwhile, AirLive.net, an aviation website, reported that one of the codes stamped on the debris was from a Boeing 777 flaperon, while a mechanic from the Réunion-based airline Air Austral told reporters that the debris had a 657-BB code. However, during a press conference, Warren Truss, Australia’s deputy prime minister, mentioned the number as BB670.

Original story:

Australia described the latest development in the search for missing Malaysia Airlines Flight MH370 as "a major lead” even as Malaysia’s transport ministry urged caution in linking it to the missing plane. On Wednesday, airplane debris was found on the island of Réunion in the Indian Ocean, which could potentially be from the missing Boeing 777-200.

Warren Truss, Australia’s deputy prime minister, said at a press conference on Thursday, that it is a “realistic possibility” that debris from Flight MH370 may have drifted as far as the Réunion Island, a French territory near Madagascar, in Africa. The current search has so far been focused on a 46,332-square-mile part of the southern Indian Ocean, nearly 2,300 miles from the island.

“A piece of debris could have floated a very, very long way in 16 months and it is a very, very long way to the Reunion islands from where we think the aircraft entered the water,” Truss reportedly said, adding that photos from the scene are “not inconsistent with a Boeing 777,” although there are “other possibilities.”

Meanwhile, Malaysia's transport ministry, which has been the subject of much criticism over its handling of the search, cautioned that no conclusion should be drawn until “tangible and irrefutable evidence” proved the debris belongs to the missing plane.

Truss reportedly added that a number seen on the debris -- BB670 -- is not a serial number but could be a maintenance code that could help speed up the investigation. 

“This kind of work is obviously going to take some time although the number may help to identify the aircraft parts -- assuming that’s what they are -- much more quickly than might otherwise be the case,” Truss said, according to the Guardian.

 Truss also reportedly said, during the press conference, that the ongoing search for the Boeing 777-200 is in the right area, adding that the current weather conditions are “very poor,” hampering the search efforts.

Earlier on Thursday, the Australian government said Malaysia would be responsible for investigating the findings on Reunion Island, which could provide long-awaited answers to the mystery of the missing plane that disappeared on March 8, 2014, with 239 people on board.

“A team comprising experts from the Department of Civil Aviation, Malaysia Airlines and the Malaysian ICAO Annex 12 Safety Investigation Team for MH370 has been despatched to Reunion Island to verify whether the flaperon belongs to the missing aircraft," Malaysia's transport ministry said, in a statement Thursday. “The Ministry would like to state that until there is tangible and irrefutable evidence that the flaperon does belong to the missing aircraft, it would be premature to speculate at this juncture. This is to ensure that we do not raise false hope for the loved ones of the victims of MH370."