The pilot was on approach to the island’s Saint-Denis Roland Garros Airport when he spotted the object at 10,000 feet.
It comes less than two weeks after a flaperon was found on Reunion Island, which was confirmed to have belonged to the MH370 plane.
“It is possible today to say with certainty that the flaperon discovered on Reunion Island on July 29 came from flight MH370,” French prosecutors said in a statement at the time.
The Boeing 777 disappeared on March 8, 2014, veering off course while en route from Kuala Lumpur to Beijing. A total of 239 people were on board.