Sao Paulo of Brazil late Wednesday were declared winners of the Copa Sudamericana, the second biggest club tournament in South America, following a fight between players and officials as the teams left the pitch at halftime.
Argentinean side Tigre accused Brazilian police of pulling guns on their players, and said they were attacked by security officials.
The alleged violence would be the latest in a series of controversies involving Brazilian police and security officials, 18 months before the country is set to host the 2014 World Cup, and just over six months ahead of next summer's Confederations Cup.
"They pulled two guns on us, the rest of the match is not going to be played," Tigre coach Nestor Gorosito told Fox Sports.
"Sao Paulo's security agents came in, they hit us with batons, took out a revolver and pointed it at the goalkeeper Damian Albil," said Tigre defender Lucas Orban. "Then the police came in and began to hit us again."
Photos of a blood-stained dressing room and comments from players saying they were hit with sticks were published in the Argentinean media.
Lucas (C) was given the captain's armband by keeper Rogerio Cerni so he was first to lift the cup on his last game
Tigre, who are based just outside Argentina's capital of Buenos Aires, refused to return to the field for the second half. The match was abandoned, and Sao Paulo were named winners of the Copa Sudamericana, a tournament that is a rough equivalent to UEFA's Europa League.
The Brazilian side were ahead 2-0 at halftime, with the first goal coming from the Paris St. Germain-bound midfielder Lucas Moura. The first leg had finished 0-0.
Controversy in Brazil
Wednesday's violence is the latest in a number of controversial incidents in Brazilian football involving police intervention.
In 2008, Botafogo defender Andre Luis was arrested on the field and marched out of the stadium by riot police. His teammates were pepper sprayed.
"It's unbelieveable that this happens in the Brazilian championship and in a country which in a few years' time is going to host the World Cup," said his Coach Abel Braga at the time.
Two years prior, police used pepper spray on players to break up an on-the-field brawl at the Vasco de Gama-Flamengo derby in Rio de Janeiro.
Violence among rival supporters is also an issue in the country. In March of this year, two fans were killed in separate incidents in the cities of Sao Paolo and Campinas respectively within the span of a week.
dr/msh (Reuters, AFP, AP)