Perez has the biggest institutions in Spain in his pocket, it's an open secret. How do you think they were able to sell a fuckin parking lot back to the city for an outrages amount? His regular guests in the VIP box are often judges, prosecutors, chief reporters of various Madrid outlets. There are even reports that he personally has to give green light when a new chief reporter for sports takes the job for a Madrid based newspaper. He controls the construction industry as well. Don't forget that Madrid TV is free to receive in Spain television.
Spain is a corrupt country in general. Look what kind of a person Rubiales was who lead the spanish football federation. Look who Tebas is, his CV in the Franco youth. Even their old King stole so much money that he now hides in Qatar, while his son doesn't look better.
Spain is on rank 35 of the corruption ranking, below countries like Botswana, Emirates and Chile.