Barcelona say payments made to a company linked to the former vice-president of the refereeing committee were for technical reports on match officials, and do not represent a conflict of interest.
Cadena Ser revealed documents on Wednesday linked to an ongoing investigation in Spain that showed Barca paid almost €1.4 million to DASNIL 95 SL between 2016 and 2018.
The payments are alleged to be for "technical advice" and "to ensure that refereeing decisions were not taken against them and [officiating] remained neutral."
DASNIL 95 SL is part-owned by Jose Maria Enriquez Negreira, who was on the refereeing committee until 2018 having previously officiated in LaLiga between 1977 and 1992.
Barca confirmed they worked with external companies to gather information on refereeing, but denied there was anything untoward about the practice and said it was common place within football.
They added they would be taking "legal action against those who are trying to tarnish the club's image with possible insinuations against its good reputation."
"Barcelona are aware of the investigations into payments of external companies and wishes to make the following clear: In the past, [the club] hired the services of an external consultant that supplied the club's technical secretaries with reports in video format of youth players from other clubs in Spain," a statement said.
"Additionally, the relationship with that supplier extended to technical reports related to professional refereeing in order to complement the information requested by the first and second team coaching staff. This a common practice among professional football clubs.
"These kinds of outsourced services are now the duty of a professional who works for the Football Department. The documents obtained by Cadena Ser suggested Barca had been sourcing such information since 2003.
"We always analyse the referees, of course, and have done for a long time," Xavi Hernandez, who returned to the club as coach in 2021 after leaving as a player in 2015, said in a news conference on Wednesday.
"For many years that has been the case, there is nothing new about that. [As for the reports], I try to focus on football but this club has these things.
"The club released a statement and I am on the same page as the club. I wasn't at the club at the time but, obviously, I defend the club's interests."
The Spanish Referee Committee subsequently issued a statement on Negreira that said they will cooperate with the investigation and insisted he would not have been sanctioned to do the work by them.
"The CTA wants to make it clear that Mr. Enríquez Negreira has not been part of any federative structure since the change of governance carried out after the 2018 elections," the statement read.
"The referee's committee regrets any behaviour that may be likely to undermine the ethics of the profession. No active referee or member of the bodies of the CTA can carry out any work that may be susceptible to a conflict of interest.
"The CTA is at the disposal of the courts to offer its complete collaboration."