A prisoner in Spain was found alive in a mortuary late Sunday, hours before scheduled postmortem examination.

Gonzalo Montoya Jimenez was found snoring by a medical examiner in the mortuary with his body marked up for an autopsy.

The 29-year-old inmate did not show up for breakfast Sunday morning and was found unconscious in his cell.

Police took him to the Institute of Legal Medicine in Oviedo for an autopsy after three doctors declared Jimenez dead at the scene.

His family was informed that he "passed away" in line with standard procedure.

Hospital sources believe it was a case of catalepsy — a nervous disorder that causes immobility nearly indistinguishable from death.

Jimenez remains in the hospital under intensive care.