A French submarine missing for over 50 years has been found in the Mediterranean.

The wreck of the Minerve, according to Agence France-Presse, was discovered off the port of Toulon, on the south coast of France, with the find announced by officials on Monday.

A private vessel reportedly found the submarine, which went missing five decades ago on Jan. 17, 1968 with 52 sailors aboard.

"We have just found the Minerve. It's a success, a relief and a technical feat," wrote Defence Minister Florence Parly on Twitter, as per a translation by Google. "I'm thinking of the families who have been waiting for this moment so long."

Nous venons de retrouver la Minerve. C'est un succès, un soulagement et une prouesse technique. Je pense aux familles qui ont attendu ce moment si longtemps. pic.twitter.com/pjDnj7lEyb — Florence Parly (@florence_parly) July 22, 2019

Several searches for the Minerve had turned up nothing over the years, AFP reports. Then, in 2019, following demands from the sailors' families to locate the submarine, Parly commissioned another search, which used newer technology to reassess data from the time of the submarine's disappearance, recreated tides in the western Mediterranean Sea, and analysed seismic reports.

According to a senior French naval officer who spoke to the news outlet anonymously, the Minerve was found 2,370 metres (7,800 feet) deep, 45 kilometres (30 miles) off the coast of Toulon by a private vessel, the Seabed Constructor, which is owned by private U.S. seabed exploration company Ocean Infinity.

Exactly how the Seabed Constructor arrived at the correct site to make the discovery, and whether it was working with Parly's team, has not been reported. Ocean Infinity declined to comment when approached by Mashable.

So, what happened to the Minerve? Well, the cause of the submarine's sinking to the seafloor has never been announced, according to AFP, as the craft itself had never been found. The Guardian reports the Minerve as having been conducting a military exercise when it disappeared.

Now, scientists can start their analysis of the sub in order to determine whether an object such as a torpedo was involved, or whether the submarine itself suffered technical faults like rudder problems.

Mashable has reached out to the French government for more information.