BUENOS AIRES — Argentina fired the head of its navy a month after a submarine disappeared in the South Atlantic with 44 crew members onboard, a government spokesman said on Saturday.

Adm. Marcelo Eduardo Hipólito Srur was let go by the defense minister, La Nación first reported. The submarine, the San Juan, has not been located and is thought to have exploded.

The vessel had been on a routine patrol off the coast of Patagonia when it last made radio contact on Nov. 15. Two weeks later, after a search and rescue mission failed to turn up any evidence of the submarine or its crew, Argentine authorities announced that the effort had become a recovery operation.

Military personnel from 18 countries took part in the initial search effort, one of the largest such missions in modern times.