Sadio Mane reportedly punched his team-mate Leroy Sane in the face in the aftermath of Bayern Munich's 3-0 loss to Manchester City in the first leg of their Champions League quarter-final.
The alleged altercation came in the dressing room following the final whistle at the Etihad Stadium on Tuesday.
Sane and Mane had been seen disagreeing on the pitch in the latter stages of the match, shortly after City had taken a three goal lead through Erling Haaland.
According to the German newspaper Bild, the discussion continued after the match with Mane having been angered by how Sane had spoken to him.