Polish official Szymon Marciniak was investigated by Uefa following his appearance at an event organised in Katowice on Monday, saying they “abhor the values that are promoted by the group”.
But they have kept him on as the referee after an apology and clarification from an anti-discrimination body.
“I want to express my deepest apologies for my involvement and any distress or harm it may have caused,” Marciniak said in a statement.
“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. Had I been aware of this fact, I would have categorically declined the invitation.”
During their investigation, Uefa said they had reached out to ‘NEVERAGAIN’, an NGO affiliated with the FARE network, which counters discrimination in European football.
“[They] raised the initial concerns about Mr Marciniak’s involvement in the event,” Uefa said.
“They requested that Mr Marciniak remain in his role as the referee for the upcoming Uefa Champions League final, firmly asserting that removing him would undermine the promotion of anti-discrimination.”
Manchester City face Inter Milan in the Champions League final at Istanbul’s Ataturk Olympic Stadium on June 10 in what could be the final step of a historic Treble.
Pep Guardiola’s side will first face Manchester United in the FA Cup final on Saturday, having already won the Premier League for a third time in three seasons.