Police used pepper spray on a player who refused to leave the pitch during a lower league game in Brazil.
Genus were trailing 3-0 to Moto Clube in a Serie D match when Robson was sent off, but he and four team-mates reacted angrily and confronted the referee.
The incident led riot police entering the field and they eventually resorted to using pepper spray as Robson resisted their attempts to remove him from the pitch. The match was subsequently abandoned.
Robson and six other Genus players have resigned over the incident, along with the coach.
Rondonia state vice-governor Joao Cahula has vowed to investigate the events.
“It’s a shame what happened on Saturday,” he told Sky News. “We are very sad with that. Football has to be played on the pitch with the players but, unfortunately, this brawl happened.
“I will talk to the police chief to take all measures necessary. If the policemen overreacted, they will be punished for that.”
