Who is the "Priest" in the novel, Hades, Argentina?

When Tomás began working in the interrogation center, the center’s operations were overseen by a man referred to only as ‘the priest.’ The priest appeared to be quite sadistic, and he attempted to cloak his sadism in false piety and morality. Through Isabel, Tomás eventually asked Montoneros to kill the priest, which they did. Afterward, Isabel, Gustavo, and Nerea had to go into hiding.