National Court judge Santiago Pedraz placed Leonardo Marcos under investigation in the Leire Díez case on July 29, 2026, and summoned him to appear on September 10 at 10:00 a.m. Marcos led the Guardia Civil from June 2023 until September 2024, when Mercedes González succeeded him. The Partido Popular had asked for him to be called as a suspect, joining proceedings examining alleged pressure on the force’s Central Operative Unit (UCO) in matters politically sensitive to the PSOE and Pedro Sánchez’s government.
The investigation concerns alleged efforts to obstruct or undermine UCO inquiries. Leire Díez, a former PSOE member, is a basic figure in the case. Reporting on the judicial material has also identified at least 39 meetings between Díez and Santos Cerdán, including 22 at the PSOE’s federal headquarters on Ferraz. Those contacts were described as potentially involving “coordination and reporting” on Díez’s activities, but meetings alone do not establish criminal liability.
Marcos’s summons brings another former senior security official into a case already involving current and former Guardia Civil leaders. Pedraz has also investigated González and Lieutenant General Manuel Llamas, the force’s deputy operational director. Both appeared before the judge in Madrid in July to answer questions about the alleged pressure campaign and internal actions involving UCO officers. Reported lines of inquiry include possible abuse of office and obstruction of justice. These remain allegations under investigation, not convictions.
The inquiry has widened beyond the UCO to alleged efforts to discredit or destabilize Beatriz Biedma, the Badajoz judge who handled proceedings involving David Sánchez, the prime minister’s brother. Biedma appeared before the National Court on October 8 as an alleged injured party and described suspected attempts to undermine her. Investigators are examining references in an agenda associated with Díez, along with testimony about an alleged approach to a person identified as “La Celsa.”
The court is also examining the PSOE’s institutional and legal relationships. On October 23, Pedraz gave the party 15 additional days to provide information about lawyers it contracted between 2021 and 2025. He required it to do so “without further delay” and rejected a request to pause the deadline while the party consulted the General Council of the Legal Profession. The order requires the party to produce documents immediately as the broader investigation continues.
The National Court has also heard testimony from PSOE staff about authorizations Santos Cerdán allegedly granted to Leire Díez, adding to the party’s legal challenges. For background on the earlier testimony, see the report on PSOE staff statements about Cerdán’s authorizations for Díez.
Spain’s legal system allows political parties such as the PP to participate in criminal proceedings through popular prosecution. The September hearing puts Marcos’s conduct within a broader judicial inquiry into alleged political influence and pressure on investigators, including actions directed at a sitting magistrate. The allegations remain under judicial examination, and the court’s investigative steps do not by themselves establish guilt.
