"That noise was analysed, the acoustic signature, and it does not correspond to a submarine, to a pattern of what would be hull blows in the Morse system, it is a continuous, constant noise, which could be biological noise", Navy Spokesperson Captain Enrique Balbi said in a statement on Monday here.
Sounds detected by probes deep in the southern Atlantic did not come from an Argentine submarine that has been lost for five days, the country's navy says, dashing new-found hope among relatives of the 44 sailors aboard. Although the submarine has enough food and fuel to last for 90 days and enough oxygen for 30 days on the surface, it only had enough oxygen to survive for seven days if submerged.
Ships and aircraft from Argentina, the United States, Uruguay, Brazil and other nations have been searching for the sub on the surface and underwater. Authorities have mainly been scanning the sea from the sky, as storms have made it hard for boats.
On Saturday, Argentina said it detected seven brief satellite calls that officials believed may have come from the missing submarine, though the origin of the calls could not be confirmed. A man walks past a banner in the colours of the Argentine national flag, outside the Argentine Naval Base where the ARA San Juan submarine that is missing at sea sailed from, in Mar del Plata, Argentina November 20, 2017.
Gabriel Galeazzi, a naval commander, told reporters that the submarine had come up from the depths and reported the unspecified electrical malfunction before it disappeared almost 300 miles off the coast.
The malfunction did not necessarily cause an emergency, Galeazzi added.
The sub was journeying from the extreme southern port of Ushuaia to the coastal city of Mar del Plata.
The ARA San Juan was inaugurated in 1983, making it the newest of the three submarines in the Argentine Navy's fleet. "We continue to do everything, deploying all available national and global media, to find them as soon as possible".
His government also sent five psychologists and a psychiatrist to the base in support of the relatives.
Approximations of oxygen in the vessel are complicated, said William Craig Reed, a former US Navy diver and submariner. The foul weather over the weekend means that it is unlikely that she could have come close enough to the surface to refresh her air.
That maintenance included the replacement of its four diesel engines and its electric propeller engines, according to specialist publication Jane's Sentinel.