PARIS — The wreckage of a French submarine that sank in 1968 with 52 crew members onboard has been found in the Mediterranean, the authorities said, ending a five-decade mystery over a vessel that was once one of the jewels of the French fleet.

“It’s a success, a relief and a technical feat,” the French armed forces minister, Florence Parly, wrote on Twitter, announcing the discovery of the vessel, the Minerve, on Sunday. “I am thinking of the families who have waited for so long for this moment.”

The wreckage was found by the Norwegian-flagged research vessel Seabed Constructor, 28 miles from the southern French port city of Toulon — and about 7,800 feet underwater. The Seabed Constructor, operated by the American ocean-mapping company Ocean Infinity, is the same craft that in November found the San Juan submarine that had gone missing in 2017 off Argentina’s coast with 44 sailors onboard.

Three parts of the Minerve were found, spread across 330 yards, said Stanislas Gentien, a spokesman for the Mediterranean’s Maritime Prefecture, in Toulon. The first four letters of the vessel’s name — MINE, written in red — were visible on the main piece of wreckage, leaving little doubt about the submarine’s identity, he said.