The Minerve submarine was lost off France's southern coast with 52 sailors on board on January 17, 1968. Despite multiple search efforts over the years, it had never been found.
France's defence Minister Florence Parly announced a new search for Minerve at the beginning of 2019, backed by the latest technology and naval vessels, following fresh demands from the families of deceased sailors to find the remains of their loved ones.
The discovery of the location of the wreck was announced on 22 July 2019. The missing submarine was found 45km (30 miles) from Toulon 2,370m (7,800ft) under the surface, AFP reports.
The cause of the accident involving the Minerve has never been announced. Experts have speculated that it could have been due to a problem with its rudder, a collision with another boat, the explosion of a missile or torpedo, or a fault with its oxygen supply systems.
The new search team reportedly re-analysed data from the accident, including tides, to help find the wreckage with the help of new technology, AFP reports. The final discovery was made by a boat belonging to private US company Ocean Discovery, an unnamed French naval official told the news agency.
"It's a success, a relief and a technical feat," Parly wrote on Twitter as she announced the discovery of the Minerve submarine.