The Argentine Navy said it has lost one of its submarines, the ARA San Juan, which holds 44 crew members. Officials didn't refer to it as an emergency, but a "communication failure."
The submarine was last contacted on the San Jorge Golf and its last position was registered on Nov. 15. It should have already been on the surface, officials said.
The TR-1700 submarine is run with diesel-electric propulsion and authorities said its purpose was to carry out surveillance exercises in the economic zone around Puerto Madryn.
Citing Navy reports, Clarin said 44 people were part of the crew, including Argentina's first submariner woman.
"The last reliable and official information is that the submarine has not yet been found, it is not that it is lost, to be lost you have to look for it and not find it," said Enrique Balbi, head of the Institutional Communication Department of the Navy.
The Navy had not published any statements but said it could have had a problem in the power supply. Officials haven't confirmed or denied a possible fire inside the battery system that stores the electrical energy equipment.
"The last communication was on Wednesday," Balbi said. "The version of the fire is not an official information, there could have been a technical failure. We still do not have communication."
This created rumors on social media, where people posted pictures of the alleged submarine and reporting that it was being towed to the Naval Base of Mar del Plata.
The TR-1700 submarine, which was built in Germany in 1986, is intended to carry out surveillance exercises in the areas surrounding Puerto Madryn.
From 2007 to 2014, the submarine underwent repairs to extend its use for 30 more years, which included repair of the 960 elements of its batteries, where officials say a failure could have originated.