Gonzalo Montoya Jiménez, 29, was believed to be dead after being found unconscious in his prison cell in Asturias, northern Spain.

After three doctors certified his death, he was transferred to a morgue in Oviedo for a post-mortem examination. Three hours after his arrival, and shortly before starting the autopsy, workers heard him snoring.

Doctors believe he was experiencing catalepsy, a symptom of some nervous disorders or conditions, local paper El Commercio reports. Catalepsy is sometimes also linked to cocaine withdrawal.

The lucky prisoner’s father said: “They were at the point of marking his chest . It’s a miracle. a miracle and a huge negligence.”