Barcelona are facing a possible Champions League ban over the Negreira case.
UEFA requested their own investigation as of Thursday, and the matter is already being pursued by prosecutors in Spain.
The governing body's Champions League regulations, which have been in effect since 2007, allow the organisation to ban teams from the competition for one season if they are found to be involved in match fixing.
Champions League regulations in effect since April 2007 allow UEFA to ban teams from the competition for one season if they were involved in fixing matches.
Court documents show Barcelona paid 7.3 million euros (6.4 million) from 2001-18 to two companies owned by Jose Maria Enriquez Negreira, DASNIL and NILSAT.
Negreira is the former vice president of Spanish football's refereeing committee.
Prosecutors in Spain have formally accused Barcelona of corruption in sports, fraudulent management and falsification of business documents, and have stated that their belief is that the club maintained a relationship with the refereeing official to ensure 'favourable decisions' were made by referees.
No evidence has yet been published that referees or individual games were actually influenced.
