Spanish police raided the offices of the referees’ committee as part of an investigation into Barcelona’s alleged corrupt payments to an official.
Barcelona face charges of corruption over payments made to Jose Maria Enriquez Negreira, a former vice-president of the committee, in return for favourable refereeing decisions.
Uefa is also investigating the matter.
Barcelona deny any wrongdoing and no arrests were made during the search in Madrid.
The Spanish Civil Guard searched the Spanish Technical Committee of Referees (CTA) headquarters yesterday.