An international team of experts began a second day of tests on the chunk of wreckage that washed up on the French Indian Ocean island of La Reunion last week.
French prosecutors were more cautious in their initial findings yesterday than Malaysian Prime Minister Najib Razak, saying only that there was a "very high probability" that the wing part, known as a flaperon, was from missing Malaysia Airlines flight MH370.
But they confirmed the part was from a Boeing 777, of the type that vanished without trace on March 8, 2014, after veering off course while flying from Kuala Lumpur to Beijing.
France has a legal involvement in the investigation because it lost four citizens in the incident.