Aleksander Ceferin, president of the European football governing body UEFA, described the referee scandal that La Liga giants Barcelona face as one of the most serious situations he has ever seen in the sport.

"The situation is extremely serious," Ceferin said in an interview with Slovenian newspaper Ekipa on Monday. "It is so serious that, in my opinion, it is one of the most serious [situations] in football that I have ever seen."

Back in March, UEFA announced that they investigated Barcelona's payments to Jose Maria Enriquez Negreira, former vice president of Spain's refereeing committee. The club gave him more than seven million euros (about $7.65 million) between 2001 and 2018 for "technical reports on refereeing," according to Barca, who denied any attempt to purchase game officials or influence.

Barcelona have won nine La Liga titles, six Copa del Rey championships and eight Supercopa de Espana titles in addition to four UEFA Champions League and three UEFA Super Cup trophies between 2001 and 2018.

Javier Tebas, president of La Liga, also called the scandal "the worst reputational crisis" he could recall in football. "I don't remember a time of such reputational crisis as this one. We have to see this through until the end. There are payments that were made and that is something that Barcelona have acknowledged. This is abnormal," he told Spanish media house, Movistar in March.

According to Tebas, La Liga can't sanction Barca because of the statute of limitations in place in Spain, but UEFA is able to do so.

"I cannot comment directly on this for two reasons. Firstly, because we have an independent disciplinary committee in charge of this. And secondly, because I have not dealt with this matter in detail," Ceferin said. "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."