Judge Juan Carlos Peinado is investigating Begoña Gómez, the wife of Spain's Prime Minister Pedro Sánchez, over allegations of influence peddling.
The inquiry was initiated after the far-right group Manos Limpias filed a complaint based on questionable media reports, many of which lacked evidence.
Despite the investigation being ongoing for over three months, no concrete proof of wrongdoing has been found.
The judge has summoned key figures, including Sánchez, to testify, raising concerns about the legality of the proceedings.
Critics argue that the investigation appears politically motivated, while the defense claims it undermines Gómez's right to a fair trial.
As the case unfolds, the implications for the government and public trust remain significant.