Uefa said Wednesday it had opened a probe into Turkey defender Merih Demiral for celebrating a goal in the team's 2-1 win against Austria at Euro 2024 with an allegedly ultra-nationalist salute.
The tournament organiser said in a statement it was investigating the player for "inappropriate behaviour" during Tuesday's knockout game in Leipzig.
The gesture, which Demiral made to the crowd after scoring his second goal of the game, is associated with Turkish ultra-nationalist group Grey Wolves.
Germany's Interior Minister Nancy Faeser on Wednesday condemned the Turkish player's goal celebration.
"The symbols of Turkish right-wing extremists have no place in our stadiums," Faeser said on X, formerly Twitter.
"Using the European football championships as a platform for racism is completely unacceptable," she added.
Speaking after the game in Leipzig, Demiral said there was no "hidden message" in his celebration.
"The way I celebrated had something to do with my Turkish identity," said Demiral, who was man of the match after scoring both Turkey's goals.
"We are all Turks, I am very proud to be Turkish and that is the meaning of this gesture."
The defender said he saw Turkish supporters in the stands using the salute.
"I just wanted to demonstrate how happy I am and how proud I am," Demiral said, adding that he hoped there would be "even more opportunities to show this gesture."
The Grey Wolves is regarded as the militant wing of Turkey's Movement Party (MHP) and has been banned in France and Austria, but not in Germany.
The group advocated radical ideas and used violence in the 1980s against leftist activists and ethnic minorities.
Following the last-16 clash, the Society for Threatened Peoples, a German human rights organisation, called on Uefa to crack down on use of the wolf salute.
The gesture was "a symbol of oppression and persecution", the NGO's Middle East lead Kamal Sido said in a statement.
Separately, Austrian forward Michael Gregoritsch also called on fans to distance themselves from "right-wing ideology".
Supporters of the Austrian team were reported during the game to have sung racist lyrics to the tune of popular dance track "L'Amour Toujours" by Italian DJ Gigi D'Agostino.
The chant – which includes the line "foreigners out" – recently caused controversy in Germany after a widely shared clip showed a group of young people singing it on a bar terrace.