Brazilian police have formally accused four Gremio fans of racially insulting a player in a Brazilian Cup match.
Police say the fans were among those who called Santos goalkeeper Aranha a "monkey," and imitated monkey noises at Arena Gremio on Aug. 28.
A judge will decide whether to charge them and, if charged and convicted, they face up to three years in prison.
The fans, identified by authorities and club officials, had already been banned from matches for two years because of their acts.
Investigators said other fans could also be charged in the coming days.
In an unprecedented ruling, a local sports tribunal eliminated Gremio, coached by former Brazil manager Luiz Felipe Scolari, from the Brazilian Cup after the insults against Aranha.