FIFA has been contacted by the Fare network relating to discriminatory chanting at the World Cup, the game's governing body has told Press Association Sport.
Allegations of the use of anti-gay language by supporters at Cameroon-Mexico and Brazil-Mexico games have been passed on to FIFA by Fare -- the organisation in place to tackle discrimination in football.
The allegations centre on the use an anti-gay slur in the Spanish language that has been heard in games in Natal and Fortaleza.
FIFA told the Press Association that while Fare had passed on concerns about both matches -- played on Friday and Tuesday -- it was already engaged in disciplinary proceedings against Mexico.
"We can confirm that we have been contacted by Fare," FIFA said in a statement. "Prior to this, disciplinary proceedings were opened against Mexico for improper conduct of spectators during the match Mexico-Cameroon. As the proceedings are ongoing, we are not in a position to comment further."
FIFA also reiterated its position against discrimination of any time.
"FIFA takes a firm, zero-tolerance stance against any form of discrimination and racism, and this is enshrined in the FIFA Statutes in Article 3, which stipulates that: 'Discrimination of any kind against a Country, private person or group of people on account of race, skin colour, ethnic, national or social origin, gender, language, religion, political opinion or any other opinion, wealth, birth or any other status, sexual orientation or any other reason is strictly prohibited and punishable by suspension or expulsion,'" it added.