Dato' Azharuddin Abdul Rahman, then the director general of the Malaysian Department of Civil Aviation, briefs the media about MH370 on March 10, 2014 in Kuala Lumpur. Getty Images

More than two years have passed since Malaysia Airlines Flight 370 disappeared en route from Kuala Lumpur to Beijing in March 2014, and investigators are still arguing over what happened. The latest development in the case came Thursday, when authorities debunked rumors that a recently discovered piece of wreckage had been charred by a fire on board the Boeing 777.

The Australian Transport Safety Bureau, which is leading the hunt for the missing plane, issued a statement about a piece of debris found by amateur searcher Blaine Gibson. Gibson gave investigators last week five items found on a beach in Madagascar, including at least two panels that appeared to have been burned — a discovery that suggested a blaze may have damaged, or crashed, MH370.

But the bureau said that the wreckage wasn't blackened by heat.

The discoloration was "related exclusively to a translucent resin that had been applied to those surfaces," it wrote. The debris' burnt smell was likely caused by something more recent than the MH370 crash, given that "burning odors would generally dissipate after an extended period of environmental exposure, including salt water immersion."

"At this stage it is not possible to determine whether the debris is from MH370 or indeed even a Boeing 777," it added.

Source: Graphiq

Ever since MH370 and the 239 people it was carrying vanished, vessels have been scanning 120,000 square kilometers of the Indian Ocean for any sign of the aircraft. But, after a series of delays, the formal sweep for debris is winding down. The hunt is expected to wrap up by December, and without new evidence, it will be suspended.

Only two pieces of wreckage have been conclusively connected to the aircraft, according to the bureau: A flaperon found near Reunion Island last year, and a wing part located near Tanzania. Both were found by civilians — not authorities involved with the costly search for plane debris.