The remains detected at 477 meters (1565 feet) under the ocean had dimensions similar to the missing ARA San Juan, but appeared to be from a sunken fishing vessel, Navy spokesman Enrique Balbi told journalists.
On Thursday authorities formally ended the search for survivors, shifting its mission from rescue to recovery.
“The extreme environment, the time elapsed, and the lack of any evidence prevent sustaining a scenario compatible with human life,” Balbi said.
The navy’s final contact with the ARA San Juan, a 34-year-old German-built diesel-electric sub, came on November 15, when it was sailing in the South Atlantic 450 kilometers (280 miles) from the coast.
In its final communication, the submarine reported it had overcome a mechanical breakdown that resulted from a short circuit due to the entry of water via the vessel’s snorkel.
Three hours later, a noise similar to an explosion was recorded 48 kilometers from where the crew had given its last report.
The position was in line with the planned path the submarine would have taken to reach its base in Mar del Plata, the navy has said.
An international armada of rescue ships backed by aircraft — and thousands of personnel — has been hunting for the submarine.
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