The final contact from the vessel, which has 44 crew members on board, reportedly said seawater had entered the ventilation system, causing a battery on the diesel-electric submarine to short-circuit and spark a fire.
Navy spokesman Enrique Balbi told reporters that the captain said water had entered through the vessel’s snorkel when its batteries were being changed.
However he also said the captain later communicated by satellite phone that the issue had been resolved.
Fifteen countries are now involved in the search for the missing vessel but there have been no signs of it or any debris.
The search area, which is concentrated 250 miles from Argentina, has been extended 22 miles from where an explosion was detected.
Chances of finding the crew alive have almost all but vanished as the crew would have used up all the available air supply by now; providing they weren’t killed in the explosion.
The rescue mission will now become a salvage operation to ensure the sailors remains are returned home to their loved ones.
Argentina’s centre-right president, Mauricio Macri, has criticised naval commanders over their handling of the crisis. According to Infobae (an Argentinian news website) Macri’s defence minister, Oscar Aguad, only learned that the submarine was missing when he read about it in the press.