Malaysia's Prime Minister Najib Razak confirms the debris found on Reunion Island is from missing Malaysia Airlines flight MH370 in Kuala Lumpur, Malaysia, early Aug 6, 2015. [Photo/Agencies]

The fragment of wing was flown to mainland France after being found last week covered in barnacles on a beach on France's Indian Ocean island of Reunion.

Despite the Malaysian announcement that the wing was confirmed as coming from MH370, prosecutors in France, where it was still Wednesday evening, stopped short of declaring they were certain, although they said there was a very strong likelihood that was the case. A piece of luggage also found in Reunion would be examined by French police.

"The real work is yet to begin" in inspecting the wing fragment, John Goglia, a former member of the US National Transportation Safety Board, told Reuters.

"They will identify everything they can from the metal: damage, barnacles, witness marks on the metal. They're going to look at the brackets (that held the flapron in place) to see how they broke. From that they can tell the direction and attitude of the airplane when it hit. There's a lot to be told from the metal."

The examination of the part is being carried out under the direction of a judge at an aeronautical test facility run by the French military at Balma, a suburb of the southwestern city of Toulouse, and witnessed by Malaysian officials.

Officials from the United States and manufacturer Boeing on hand. Boeing declined to comment.