The Seabed Constructor, a ship owned by US search firm Ocean Infinity, made the discovery Friday, one day after the first anniversary of the disappearance of the San Juan.
The ship had set out in September on the latest attempt to find the San Juan, whose disappearance cost the navy’s top officer his job.
There has been “positive identification of the ARA San Juan,” at a depth of 800m (2,600ft), the navy said on Twitter, confirming the vessel had imploded.
The navy lost contact with the submarine on November 15, 2017, about 450km (280 miles) from the Argentine coast while it was travelling northward from the country’s southern tip.
Admiral Jose Villan, the navy’s new head, said that the rough terrain on the ocean floor made it difficult for search vessels, which had already trawled the site, to find the sub.
Pieces of the submarine that were 11, 13 and 30 meters long were spotted in “an irregular, moon-like zone with craters and canyons” naval Captain Enrique Balbi said at a conference, adding that the hull had been “crushed inwards.”
“I still had hopes that they could be alive,” Luis Niz, the father of a missing sailor, told reporters, even though President Mauricio Macri’s government had already declared there were no survivors.
“We are with the other relatives. They are going to show us the photos. They say that our youngsters are inside,” said Yolanda Mendiola, the mother of crewman Leandro Cisneros, 28. “We are all destroyed here.”
Relatives are now asking for authorities to extract the submarine, though whether such an operation will be undertaken remains unclear.
“Raising the submarine to the surface is not impossible, but it is a very complex operation, and therefore very expensive,” a naval officer told AFP, requesting anonymity.
The discovery came the day after a sombre ceremony, which Macri attended, at the San Juan’s Mar del Plata base on the first anniversary of its disappearance.
It also came just before the Seabed Constructor was to leave for maintenance in South Africa.
Before setting off, the searchers decided to check an area which bad weather had previously prevented them from examining.
The Seabed Constructor is equipped with cameras that can be submerged to a depth of 6,000m.
It was to receive a reward of $7.5mn if it found the missing sub.
Before the latest search mission began, Luis Tagliapietra, whose son Alejandro was a lieutenant on the San Juan, described it as “the last opportunity to find them.”
Ocean Infinity was also assigned the task of hunting for Malaysia Airlines flight MH370, which vanished without trace in March 2014 en route from Kuala Lumpur to Beijing.
Experts say the sub would have been crushed by water pressure once it dropped below about 600m.
They believe that water seeped inside through a defective valve of the submarine’s snorkel, triggering the tragedy.
The loss of the San Juan was one of the world’s worst submarine disasters in decades, and the first major tragedy to hit Argentina’s navy since the Falklands War in 1982.
Argentina, which refers to the islands as Las Malvinas, lost the war to Britain.
Argentina’s navy has been fiercely criticised for its handling of the case since first reporting the submarine overdue at Mar del Plata on November 16, 2017.
It was only several days into the tragedy that navy officials acknowledged the old, German-built submarine had reported a problem with its batteries in its final communication of November 15.
Nearly 10 days later, the navy confirmed there had been an explosion on board, which experts said was likely linked to the battery problem.
An air and sea search involved 13 countries, but most of them withdrew before the end of 2017.
Authorities have opened a criminal investigation.
Families of the missing crew had kept pressure on the government not to give up the search.
“We want to know what happened,” said Yolanda Mendiola, calling for punishment of anyone guilty in the case.
