Catalan police say they made four arrests after searching the office of Spanish Barcelona.
The identity of those involved has not yet been confirmed by the police, who said that their investigation is continuing.
The police operation was carried out on Monday after an investigation into financial problems in Barcelona.
The club’s presidential election is being held on the Sunday following their previous president, Josep Maria Bartomeu, announced his resignation in October.
According to Spanish media reports, Bartomeu is among those arrested – although police have not confirmed it.
In a statement, Barcelona he said police searches related to “contacting surveillance services on social media”.
“FC Barcelona has offered full cooperation to the legal and police authorities to help draft clear facts that are the subject of an investigation,” the club said.
“The information and documentation requested by the judicial police are strictly relevant to the facts of this case.
“FC Barcelona expresses its utmost respect for the existing judicial process and the principle of the presumed innocence of the people affected by this investigation.”
According to reports in Spain, the investigation relates to the ‘Barcagate’ scandal in February 2020, when the club was forced to refuse to hire a firm that would attack its own players on social media.
Andy West, a football writer from Barcelona
The idea of one of the world’s most prestigious football clubs hiring a social media company to run a secret defamation campaign against its own players and their families seems far from conscious.
But given the onslaught that Barca’s reputation has taken hold of former President Josep Maria Bartomeu, this may be an almost logical development.
This story has been buzzing for more than a year and is one of the sources of a deep rift between the old board and the playing team that led captain Lionel Messi to stop trying to leave the Nou Camp last summer, and eventually led to Bartomeu’s late resignation.
Perhaps the saddest thing is that no one around Barcelona would be particularly surprised if the accusations turned out to be true.
It is an ironic moment of police action on Monday, which comes just days before Bramomeu’s disgraced successor was anointed in the presidential election.
Whoever wins that vote of the club members, the news from Monday painfully shows that, apart from rebuilding the world-class team on the field, the task of restoring Barca’s ruined reputation that “more than the club” is equally huge.