France just confirmed that the debris found on Reunion Island is from missing Flight MH370

France has confirmed that debris that washed up on a French island in the Indian Ocean recently is from missing Malaysian Airlines Flight MH370, a Paris prosecutor announced on Thursday.

Researchers had said in July that the debris was almost certainly from the plane, but there was no official confirmation from France until now.

"It is now possible to state with certainty that the flaperon found on July 29, 2015 corresponds to the flight MH370," French investigators said in a statement, according to NBC News.

This leaves little doubt that the plane crashed into the ocean last year, but it's still unclear what caused the catastrophe.

The piece of the plane that was found is called a "flaperon" and comes from the wing.

Former US National Transportation Safety Board investigator Greg Feith told Bloomberg last month that since the piece was not "crushed," experts could "deduce it was either a low-energy crash or a low-energy intentional ditching." Investigators determined shortly after the plane disappeared that it likely crashed in a remote part of the southern Indian Ocean.

MH370 disappeared on March 8, 2014, while flying from Kuala Lumpur, Malaysia, to Beijing. It had 239 passengers and crew on board.