UEFA president Aleksander Ceferin said the refereeing scandal facing Barcelona is one of the most serious situations he has ever seen in football.
European football's governing body announced in March it had opened an investigation into payments Barca made to the former vice president of Spain's refereeing committee.
From 2001 to 2018, Barca paid over €7 million to Jose Maria Enriquez Negreira. The Catalan club say they were purchasing "technical reports on refereeing" and deny ever buying match officials or influence.
"The situation is extremely serious," Ceferin said in an interview with Slovenian newspaper Ekipa on Monday when asked about the events surrounding Barca.
"It is so serious that, in my opinion, it is one of the most serious [situations] in football that I have ever seen," he said.
Prosecutors are pursuing charges against Barca for alleged corruption, with a court in Spain recently agreeing to open an investigation into the club and former presidents Sandro Rosell and Josep Maria Bartomeu.
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LaLiga president Javier Tebas has called the scandal "the worst reputational crisis" he can remember in Spanish football and called on Barca president Joan Laporta to clear up the payments.
Laporta said he plans to hold a news conference once an internal investigation concludes.
However, Tebas has also confirmed LaLiga will not be able to sanction Barca because of the statute of limitations in place in Spain -- although Ceferin revealed UEFA don't face such restrictions.
"I cannot comment directly on this for two reasons," Ceferin added. "Firstly, because we have an independent disciplinary committee in charge of this. And secondly, because I have not dealt with this matter in detail.
"At the level of [LaLiga], of course, the matter is time-barred and can have no competitive consequences, but the proceedings are ongoing at the level of prosecutors. But as far as UEFA is concerned, there is nothing time-barred."