Iturriaga, once a prominent member of Pinochet's security services, was sentenced to five years in prison for kidnapping Luis San Martin in 1974. The whereabouts of San Martin, who was 22 at the time, are still not known.
Jose Miguel Vivanco of Human Rights Watch told Al Jazeera that Iturriaga's challenge of the judicial decision was unprecedented.
Vivanco said that unless Chile could enforce the sentence, it might have a domino effect and encourage others facing similar charges in the region to follow the example of Iturriaga.
"It is absolutely critical that the Chilean government enforces the rule of law," he said.