The South American Cup (Copa Sudamericana) final in Sao Paulo was abandoned at half-time when players from Argentine side Tigre claimed they were attacked by Brazilian security forces in their dressing room.
Tigre refused to emerge for the second half of Wednesday evening's second leg tie against Sao Paulo, leading to the game being abandoned and the title awarded to the Brazilian team.
Tigre defender Lucas Orban said police barged into their dressing room and threatened one of the club's players with a gun.
"Sao Paulo's security agents came in, they hit us with batons, took out a revolver and pointed it at the goalkeeper Damian Albil. Then the police came in and began to hit us again," he reported.
The astonishing claims came just two weeks after the draw was held here for the 2013 Confederations Cup and in the country that is hosting the 2014 World Cup.
Tigre midfielder Martin Galmarini reported that "everyone was armed".
He said Sao Paulo's security agents were lying in wait for the Tigre players at the entrance to their dressing room "and threatened us with weapons".
The Tigre players' claims were denied by a Brazilian military policeman.
"No one was armed," commander Gonzaga told Brazilian media.
According to Gonzaga, when the police arrived "there was general fighting between Sao Paulo security, the players and the Tigre staff. No one was armed, there were people wounded on both sides."
Chilean referee Enrique Osses officially called off the game when the Argentinian players refused to take to the pitch for the second half with the South American Football Confederation (Conmebol) awarding the title to Sao Paulo.
The match had already been marred by scuffles between the two sets of players in the first half triggered by a foul on Sao Paulo's Lucas Moura.
Moura, who was making his last appearance for Sao Paulo before joining French side Paris Saint Germain, scored the opening goal in the 23rd minute, with Osvaldo doubling up six minutes later.