The Secretariat General of Prisons has decided to charge "at least" six officials from the Sevilla-I prison with gross misconduct, reports online daily La Crónica de Andalusía.
The guards were discovered sleeping during a routine inspection of the nightshift on May 8th, which coincided with the resignation the following morning of the warden, Ana Isabel Martín Díaz.
Prison sources informed journalists that "serious charges" have been filed against five officers and the chief of the nightshift which will be investigated in the coming days by the Secretariat's prison inspectors to determine the facts.
According to the same sources, one of the guards has been accused of "neglect of duty" while four others face accusations of "putting prison security at risk".
The chief of nightshift will be held responsible for any incidences that occurred during his watch.
The Secretariat General has not yet decided whether or not to accept the resignation of the prison warden, earlier tendered for "personal reasons", after opening the investigation into the prison staff.
Ana Isabel Martín Díaz, previously the warden of Cordoba's prison, took over at Seville in 2010 when the former director there was sacked following a breakout which led to the escape of two prisoners.
Both men were later located and arrested in Lleida before returning to the prison to carry out the remainder of their sentences.