FIFA insist their security plan for the 2014 World Cup in Brazil will prevent any repeat of the violent scenes which halted the Copa Sudamericana final - with visiting players claiming there were threatened with guns by security officials.
Brazilian hosts Sao Paulo were crowned champions after Argentinian side Tigre refused to return for the second half at the Morumbi stadium, claiming their players had been attacked by security staff in the dressing rooms during the interval.
It followed confrontations between the two sets of players as they made their way off the pitch at half-time with Sao Paulo 2-0 up.
FIFA said in a statement: "FIFA cannot comment on the incidents at the match in question, as FIFA were not involved in this match operation.
"However, for the FIFA Confederations Cup and the FIFA World Cup there will be a comprehensive security concept for the stadiums in place developed by the local organising committee together with the respective authorities and reviewed by the FIFA security experts.
"The FIFA Confederations Cup will be the first football competition in Brazil to use mainly private stewards for safety and spectator services as it is already a standard procedure in many countries around the world.
"This is already a legacy as through this initiative more than 30,000 security officers will be trained and certified to work during the FIFA Confederations Cup and FIFA World Cup in Brazil. FIFA has full confidence in the security arrangements developed."
Tigre goalkeeper Damian Albil said one officer put a gun to his chest.
He said: "The fight lasted 15 minutes. A lot of security people came to us and attacked us. Suddenly, I realize that I had a gun against my chest.
"If we did go out to play, it would be a battle in the field. There was no security, it was impossible to play. Something worse could have happened."
Tigre assistant coach Jorge Borrelli added: "It was unbelievable, I have never seen anything like this. We're lucky someone wasn't killed."
Sao Paulo's president Juvenal Juvencio claimed the Argentinian side had been intimidated by the atmosphere and denied that guns had been produced.
He said: "They were there with their tongues out with fear because we had 67,000 fans in the stands. They knew they were to going to concede many more goals in the second half, so they decided to leave.
"There were no guns as they said. Tigre is a small team - nobody had heard of them 15 days ago.
"We will celebrate twice: the Argentinians' runaway was our biggest victory."
The South American governing body CONMEBOL must now decide whether to punish Tigre for not playing the second half, or Sao Paulo for the lack of security in their stadium.
CONMEBOL official Romer Osuna said: "The referee abandoned the game because it was not right to play on.
"This decision is final. It is a shame that a continental final finished in this fashion."
Sao Paulo captain and goalkeeper Rogerio Ceni was shocked by the way the match ended, but claimed the Tigre players had been overly aggressive on the pitch.
"We don't know what happened, but the Tigre players came to Brazil to fight, not to play," he said.
"I really don't know what happened in the dressing rooms."