Barcelona’s offices were searched on Monday morning and Catalan police made an unconfirmed number of arrests.
Police said detentions were made but did not say who or how many people were taken into custody.
The club issued a statement on Monday saying: “Regarding the entry and search by the Catalan Police force this morning at the Camp Nou offices by order of the Instructing Court number 13 in Barcelona, which is in charge of the case relating to the contacting of monitoring services on social networks, FC Barcelona have offered up their full collaboration to the legal and police authorities to help make clear facts which are subject to investigation.
“The information and documentation requested by the judicial police force relate strictly to the facts relative to this case.
“FC Barcelona express its utmost respect for the judicial process in place and for the principle of presumed innocence for the people affected within the remit of this investigation.”