A video posted online appears to show former Barcelona and Cameroon striker Samuel Eto'o lashing out at a man following a match at the World Cup in Qatar.
The incident occurred outside Stadium 974 in Doha after Monday's last-16 match between Brazil and South Korea, which the South Americans won 4-1.
Eto'o, who is now president of his country's football federation (Fecafoot), posed for several pictures with supporters before getting into an angry altercation with another man with a video camera.
Footage showed Eto'o advancing towards the man before he was restrained by bystanders, but the 41-year-old then broke free and appeared to lash out towards the man with his knee.
The four-time African Footballer of the Year is also an ambassador for Qatar's Supreme Committee for Delivery & Legacy, which is overseeing the organisation of the World Cup alongside world governing body Fifa.
Fecafoot and the Supreme Committee have been contacted for comment.
Eto'o, who scored 56 goals in 118 games for Cameroon, was elected Fecafoot president in December last year.
He also had playing spells at Real Madrid, Mallorca, Inter Milan, Chelsea and Everton.