FIFA has been contacted by the Fare network relating to discriminatory chanting at the World Cup, the game's governing body has told PA Sport.
Allegations of the use of improper language by supporters at games between Brazil and Mexico and Cameroon and Mexico have been passed on to FIFA by Fare (Football Against Racism in Europe) - the organisation in place to tackle discrimination in football.
The allegations centre around the use of the word 'puto' which translates into 'whore' and has been heard in games in Fortaleza and Natal.
FIFA told the Press Association that while Fare had passed on concerns about both of the matches - played last Friday and on Monday - it was already engaged in disciplinary proceedings against Mexico.
It said in a statement: "We can confirm that we have been contacted by Fare. 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 on 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'."