Referee Szymon Marciniak will officiate next weekend's UEFA Champions League final after apologizing for his appearance at an event organized by a hardline right-wing Polish politician, the European football governing body confirmed in a statement on Friday.

According to the Guardian, Marciniak was a keynote speaker at an event entitled "Everest" organized by Slawomir Mentzen, the leader of the nationalist Confederation party in Katowice, Poland on Monday.

The party is known for its slogan, "We stand against Jews, gays, abortion, taxation and the European Union," the Guardian reports.

UEFA says it launched an investigation after the Never Again Association, an anti-racist NGO in Poland, raised concerns about Marciniak's participation in the event.

The association is affiliated with the Fare network -- an umbrella organization which fights inequality in football.

Never Again's co-founder had called on Marciniak to apologize, expressing shock over his "public association with Mentzen and his brand of toxic far-right politics," the Guardian reports.

Marciniak, who refereed the World Cup final between Argentina and France in December, said he was "gravely misled and completely unaware" of the event's affiliation.

"I want to express my deepest apologies for my involvement and any distress or harm it may have caused," Marciniak said in a statement shared by UEFA.

"Upon reflection and further investigation, it has become evident that I was gravely misled and completely unaware of the true nature and affiliations of the event in question. I had no knowledge that it was associated (with) a Polish extreme-right movement," he added.

UEFA said it acknowledged the referee's "profound apologies," adding that the Never Again Association had requested the referee remain in his role "firmly asserting that removing him would undermine the promotion of anti-discrimination."

Marciniak will serve as the referee for the Champions League final match between Manchester City and Inter Milan on June 10 in Istanbul, Turkey.