An anti-racism group on Thursday called on the head referee of the Champions League final to distance himself from a far-right politician in Poland, and UEFA said it wanted "urgent clarification" ahead of the Champions League final.
"A further announcement will be made [Friday], after reviewing all the evidence," UEFA said.
Szymon Marciniak has been picked by UEFA to referee the biggest game in club soccer between Manchester City and Internazionale on June 10. He also handled the Argentina-France World Cup final for FIFA this season.
The Never Again group in Warsaw said Marciniak "reportedly promoted and participated in a recent event organized by a Polish far-right leader Slawomir Mentzen."
'We are shocked and appalled by Marciniak's public association with Mentzen and his brand of toxic far-right politics," Never Again co-founder Rafal Pankowski said in a statement. "It is incompatible with the basic values of fair play such as equality and respect."
Mentzen is a leader of the populist Konfederacja (Confederation) party which has been accused of promoting anti-semitic, sexist and anti-gay views.
Marciniak was billed as a key speaker at an event publicized as a business conference for entrepreneurs on Monday in Katowice, Poland. Mentzen promoted the referee's involvement on his social media channels.
UEFA said in a statement "the whole football community abhor the 'values' that are promoted by the group in question and takes these allegations very seriously."
Pankowski said Never Again called upon Marciniak "to acknowledge his mistake. If he does not do it, we believe UEFA and FIFA should draw consequences."
The 42-year-old Marciniak refereed at the 2022 and 2018 World Cups and the 2016 European Championship. He missed Euro 2020 while recovering from a heart complaint after a COVID-19 infection.