Fabrice Wislez, Associated Press
Workers for an association responsible for maintaining paths to Jamaica beach from being overgrown by shrubs, search the area for possible additional airplane debris near the shore where an airplane wing part was washed up, in the early morning near to Saint-Denis on the north coast of the Indian Ocean island of Reunion Sunday, Aug. 2, 2015. A barnacle-encrusted wing part that washed up on the remote Indian Ocean island earlier could help solve one of aviation's greatest mysteries, as investigators work to connect it to the Malaysia Airlines Flight 370 that vanished more than a year ago with 293 people aboard.

PARIS — French investigators have formally identified a washed-up piece of airplane debris found in July on a remote island in the Indian Ocean as part of Malaysia Airlines Flight 370, a Boeing 777 that disappeared more than a year ago with 239 people aboard.

Investigators have been examining the wing part, called a flaperon, since it was flown to a French aeronautical research laboratory near Toulouse last month. Malaysian authorities had already declared that the wing fragment was from the missing jet, but until now French investigators couldn't say with certitude that it was the case.

The Paris prosecutor's office said in a statement Thursday that investigators used maintenance records to match a serial number found on the wing part with the missing Boeing.

"Today it is possible to state with certitude that the flaperon discovered on Reunion July 29, 2015 corresponds with that of Flight MH370," the prosecutor's statement said.

The flight disappeared March 8, 2014.