Liverpool footballer Darwin Núñez was involved in an altercation with spectators after his national team, Uruguay, was beaten on Wednesday evening.
The striker was seen physically confronting Colombia fans in the stands after the final whistle in the Copa America semi-final.
According to Uruguayan outlet El País, disorder broke out close to where friends and family members of the Uruguay team were located.
Núñez has yet to comment publicly on the incident.
TV cameras and fans captured images of Núñez climbing up railings and making his way into the crowded stands of the Bank of America Stadium in Charlotte, North Carolina. He was seen confronting Colombia fans as others tried to restrain him.
Other Uruguay players were reportedly involved in the incident.
Uruguay captain José María Giménez said the players were trying to defend their families, describing the situation in the crowd as a "disaster," Reuters reported.
He continued: "There was no police, and we had to defend our families. This is the fault of two or three people who had a few too many drinks and don't know how to drink."
Núñez was later seen hugging his son on the pitch after the altercation.
South American football's governing body, Conmebol, "strongly condemned" the incident and said it would launch an investigation. "There is no place for intolerance and violence on and off the field," it added.
The brawl occurred after Uruguay slumped to a 1-0 defeat against Colombia in the semi-final, denying them a place in Monday's Copa America final.
Shortly before the crowd disorder began, players and coaching staff had clashed on the pitch after the match ended.
Núñez started the game up front for Uruguay but could not convert any of his four attempts on goal.
Liverpool signed the forward for an initial £64m from Portuguese side Benfica in June 2022. He has scored 20 goals in 65 appearances for the club.
Colombia will play Argentina in Monday's final.