The search continues for ARA San Juan and the 44 crew members on board after a noise detected undersea proved to be a false alarm.
Experts determined the “noise” did not come from tools being banged against the hull of a submarine, as had been reported.
Navy spokesman Enrique Balbi said the sound – heard about 220 miles from the Argentine coast and at a depth of about 650ft – likely came from a “biological” source.
This is the latest setback for their operation. On Saturday, there was hope that the crew may have attempted to make contact through seven failed satellite calls – but it later emerged that these too were unrelated.
President Mauricio Macri tweeted that the Argentine government would “continue to deploy all available national and international resources” to find the submarine.
Argentina is now being assisted in its search by the UK, US, Brazil, Chile and Uruguay.
Search units have been using information gathered from British Ice Patrol Ship, HMS Protector, which is equipped with an underwater search probe. Although waves of up to 10m have hampered progress.
Search continues for #ARASanJuan , waves of up to 10m have hampered progress with conditions easing slightly overnight leading to improved sonar conditions. Aircraft and ships from many nations taking part in this truly multinational air and sea search effort. pic.twitter.com/pNFfOh9S40
— HMS Protector (@hmsprotector) November 20, 2017