Cadena SER reports on Monday morning, police raided the premises of FC Barcelona as part of the Barçagate investigation.
Bartomeu has been accused of having used a communication agency to discredit his opponents including some Barca players, including Gérard Piqué and Lionel Messi.
Last September, it was reported that the Catalan police had filed a report to the judge investigating Barcelona's hiring of social media consultancy I3 Ventures and 'possible economic crimes'.
It was claimed that these accounts ran negative stories about club figures who were in potential opposition to Bartomeu. One of the stories referred to Messi's wife Antonella.
Back in July 2020, an investigation by audit company PricewaterhouseCoopers cleared Barcelona of any wrongdoing and ruled they did not commission I3 Ventures to run a smear campaign against important club figures.
Bartomeu has now been detained by police after the search. The other people arrested in this case include Óscar Grau, who was the club's general manager, and Román Gómez Pontí, head of legal services.