Itatí Leguizamón, 29, the wife of Germán Suárez, 32, an engineer on the submarine, said the crew had been worried about the state of maintenance of the vessel.
“My husband told me there were problems,” she said.
Ms. Leguizamón said that she and other relatives felt the navy had withheld information during the search.
“They deceived us,” she said. “They manipulated us.”
Experts have said that if the San Juan was intact but submerged, its crew might have only enough oxygen to last seven to 10 days.
The United States Navy, which is helping with the search, shared the information about the catastrophic explosion with the Argentines on Wednesday, according to Captain Balbi.
The International Atomic Energy Agency, a Vienna-based organization that monitors seismic activity across the globe for signs of nuclear tests, supplied corroborating information about the explosion, via the Argentine ambassador in Austria, on Thursday morning.
After analyzing the two pieces of information, the Argentine Navy broke the news initially to relatives and then, minutes later, to journalists assembled at a base in Mar del Plata.
The submarine was not armed with nuclear weapons and the explosion was not believed to have involved a nuclear weapon, Captain Balbi said.
The two reports about an explosion — from the United States Navy and from the International Atomic Energy Agency — each provided a radius of about 77 miles, and that area is now being searched, Captain Balbi said.
He said there was no way of knowing what had caused the accident.
“Unfortunately, we don’t have that information: what may have been the cause in that location, on that day, of an event of these characteristics,” Captain Balbi said.
The news on Thursday followed a string of reports that had raised and then dashed the hopes of the sailors’ families.
They included an account about satellite phone calls having been made from the submarine, which turned out to be false, and recordings of sounds that were described in news reports as possibly having come from sailors banging on the hull of the vessel to alert rescuers. That report, too, turned out to be unfounded.