An Argentine navy spokesman says that water recently entered the snorkel of one of its submarines and caused one of its batteries to short circuit.
Enrique Balbi adds that the incident involving the ARA San Juan occurred before the vessel vanished 12 days ago.
“[It] caused a short circuit and the beginning of a fire, or smoke without flame,” he told reporters in Buenos Aires, Argentina’s capital city, Monday.
“They had to electrically isolate the battery and continue sailing underwater to Mar del Plata using another battery circuit,” Balbi added of the San Juan’s crew.
Balbi noted that the San Juan’s captain said water had entered the craft through the snorkel when it was changing batteries.
The water then went through a ventilation system and into a battery connection tray in the San Juan’s prow.
The captain next reported the electrical issue, prompting Argentina’s navy to order the San Juan to return to its base in the coastal city of Mar del Plata.
Balbi added that the captain later communicated by satellite phone that the problem had been contained.
The ARA was last heard from on Nov. 15, and there have since been zero signs of the submarine or related debris despite an extensive multinational search.
Experts have said that the 44 sailors aboard had only enough oxygen for 10 days if the vehicle remained intact but submerged.
Argentina’s navy announced last week that an explosion had been detected near the place and time where the San Juan was last heard from.
The military branch now says more than 12 countries remain hunting for the submarine in an area where the noise was recorded roughly 270 miles off Argentina’s coast.
The San Juan is a German-built diesel-electric TR-1700 class submarine which was commissioned in 1985 and was most recently refitted in 2014.
Argentine President Mauricio Macri has vowed to probe the San Juan’s disappearance, while some of its crew’s family members have hammered their navy’s response to the incident.
The Associated Press contributed to this report.