Football's world governing body Fifa has cleared Mexico of improper conduct charges after claims their fans used homophobic chants at a World Cup match.
The fans shouted the Spanish word "puto" ("male prostitute" in Mexican slang) every time Cameroon's goalkeeper took a goalkick at the game on 13 June.
But Fifa now said the incident in question "was not considered insulting in the specific context".
A leading anti-discrimination organisation criticised Fifa's move.
Fare, which brings together activists also fighting inequality in football, said the ruling by Fifa's disciplinary committee was "disappointing".
It added that the governing body needed to take some difficult decisions at times.
Tough new rules to stop offences by fans were introduced by Fifa last year.
Fifa sources have told the BBC they are also looking into alleged discrimination by fans from Brazil, Russia and Croatia.
Fifa's anti-discrimination policy says a first offence by fans or players can be punished by having to play a game behind closed doors.
Subsequent or more serious offences can be punished by deducting points, relegation or expulsion from a competition.
Fifa officials say they also have evidence of banners belonging to a number of far-right groups being displayed at Russia's game against South Korea and Croatia's match with Brazil.
Leading Fifa executives have repeatedly stated that financial sanctions have no deterrent effect.