Dunga bars media from training
Television pictures showed defender Daniel Alves and striker Julio Baptista having an altercation during Friday's practice, the second time an internal disagreement has been reported since the team arrived in South Africa.
Defensive midfielder Felipe Melo criticised the reporting of the incident on Saturday.
"We have a great harmony here, it is ridiculous to say there was a fight," he told repoters.
Hundreds of journalists follow the Brazilian team and some radio stations carry live broadcasts of training sessions.
The previous incident involved Kaka and Felipe Melo who made a point of hugging each other in front of the cameras after it was reported they had an argument over a tackle.