There is a "very high probability" that wreckage found on the Indian Ocean island of La Reunion comes from the doomed Malaysia Airlines flight MH370, a French prosecutor said Wednesday.

"There exists a very high probability that the flaperon indeed belongs to flight MH370," said deputy Paris prosecutor Serge Mackowiak.

His statement was considerably more cautious than one minutes earlier from the Malaysian prime minister, who said the investigation had "conclusively confirmed" the debris came from the flight.