Barcelona are currently being investigated for sporting corruption and bribery, due to payments of €7-8m over a period of 17 years to former Vice-President of the Referees Committee Jose Maria Enriquez Negreira. However the outlet that has revealed many of the more recent twists in the legal case suggest that the simultaneous investigation regarding misappropriation of funds could be more fruitful for the prosecutor.
Thus far, no evidence has been found of Barcelona making payments to referees directly, or Negreira himself doing so in exchange for favourable treatment. Equally, it remains to be seen whether Negreira could be considered a public official, and therefore whether the bribery charge would apply.
El Mundo recently revealed that the Court Magistrate directing the investigation Joaquin Aguirre has asked the police to investigate the mid-level management at Barcelona in order to establish how they operated, including requesting internal club communications. Now the same paper are saying that in private Negreira has remarked that the money he was paid, subsequently withdrew in cash, and seemingly has not been spent by Negreira, returned to the offices at Barcelona.
This does not rule out the above being strategy as part of an effort to pay for refereeing favours, but certainly would suggest that the money was not necessarily aimed at those refereeing the matches themselves.