A scandal broke in May when it was revealed that the University’s basement contained over 250 dead bodies which had been donated to science.

They had been kept at room temperature, resulting in a scene described by witnesses as “a chamber of horrors” and “the stuff of nightmares”.

Spain’s El Mundo newspaper, which reported the story, told of “blackened feet” in bins and rows of “mummified corpses”.

An investigation into the ghoulish goings-on prompted union staff to admit that four of its members, all technicians, had received “cash in hand” sums of “ranging from €100 to €150” per day in return for preparing the cadavers for use in extra classes, often held at weekends.

They admitted to up to 23 occasions when bodies had been used clandestinely, mainly for studying ophthalmology (eye anatomy) and dentistry.

Instead of working under the cover of night, the staff worked under the cover of “ongoing education”, charging for their services but failing to officially declare them.

Union sources said that the staff were “scared to death”.

“Sometimes they had to work overtime and were present during the classes, at less than €10 per hour, and sometimes they were asked to leave the bodies ready on a Friday before they left and then collect them on Monday when they arrived,” the source added.

José Carillo, the University’s Rector, said that the issue of payments fell “under the umbrella of classified information” but highlighted that “If someone has charged cash-in-hand then that is completely irregular.”

José Ramón Mérida, head of the anatomy department, refused to comment but Professor José Francisco Rodríguez Vázquez, who has been at the University for 33 years, said that his colleague was going through “the worst time of his life” as a result of the scandals.

Prof. Rodríguez Vásquez said that he had never delivered an unsanctioned extracurricular class and that he personally knew nothing about the matter and but noted that “This department has five floors and I work on the second, not in the basement.”