UEFA are reportedly targeting a decision by June on whether Barcelona will be banned from next season's Champions League, following the discovery that the club paid millions of dollars to companies linked to a Spanish refereeing official.
Barcelona have been charged with corruption by prosecutors over alleged payments made by the club to the then vice-president of the Spanish referees' committee.
The club has been accused of maintaining a relationship with Jose Maria Enriquez Negreira in which 'in exchange for money' he carried out actions that would 'lead to Barcelona being favoured in the decision making of the referees'.
The prosecution says €7.3million (£6.46m) was paid by the club to DASNIL and NILSAT, two companies owned by Negreira.
UEFA requested its own investigation into the case last month, with the governing body able to ban teams from the Champions League for one season if they are found to have been involved in match fixing under the competition's regulations.
According to Spanish newspaper Marca, UEFA want investigators Jean-Samuel Leuba and Mirjan Koller to conduct a quick process to resolve the case before next season's competition.
The governing body reportedly wants a decision to be reached in June over Barcelona's status.
This would allow for potential appeals by Barcelona to the UEFA's Appeals Body and the Court of Arbitration for Sport, in the event the club were sanctioned over the case.
Barcelona are set to qualify directly to the group stage of next year's Champions League, with the Catalan club currently holding a 12-point lead at the top of La Liga.
UEFA president Aleksander Ceferin said he had been informed about the seriousness of the case.
'I have been informed and the situation is extremely serious. It is so serious that, in my opinion, it is one of the most serious in football that I have seen,' Ceferin told the Slovenian newspaper Ekipa.
Ceferin said he could not comment further on the case, due to the investigation being handled by an independent disciplinary committee.
The controversy first hit Barcelona in February when an investigation into a firm owned by Negreira revealed a £1.2m payment from the club, during a two-year period until 2018 for 'technical advice on referees'.
Spanish newspaper El Mundo subsequently reported that payments from Barcelona to Negreira's company date back to 2001, a period of time that includes Joan Laporta's first spell as club president. He will now have to give evidence to investigators.
At the time Barcelona issued a statement admitting to having contracted the services of an 'external' consultant who provided reports 'related to professional refereeing in order to complement information required by the coaching staff', something that it said was 'common practice in professional football clubs'.
Later El Mundo revealed that when Barcelona stopped paying Enriquez Negreira, lawyers faxed them referencing a relationship that had 'lasted so many years with so many favours rendered and so many confidences shared'.
Laporta was asked about the scandal at the start of March and said: 'Barca has never bought referees and Barca has never had any intention of buying referees. Absolutely never.
'The forcefulness of the facts contradicts those who try to change the story.'
Barcelona's former directors have reportedly claimed the payments were made as 'an act of self-defence',
No evidence has yet been published that referees or individual games were actually influenced.
Barcelona has consistently denied any wrongdoing or conflict of interest, saying it paid for technical reports on referees but never tried to influence their decisions in games.