A police sniper asked permission to open fire on an armed man seen approaching Brazilian President Dilma Rousseff and other officials as they watched the June 12 opening game of the World Cup, law enforcement authorities said Friday.
Permission was denied and the suspected assailant turned out to be another policeman.
More than 60,000 spectators had packed the Itaquerao Stadium to watch the match.
Adriano Moneta, a press officer with the Sao Paulo state security secretariat that oversees security forces, confirmed the incident and said, "There was a communications error that was quickly fixed." He would not reveal further details.
The Folha de S. Paulo newspaper that first reported the story said the sniper saw an armed man in a police uniform approach Rousseff, FIFA president Sepp Blatter and UN Secretary-General Ban Ki-moon.
Fearing the man was a gunman disguised as a police officer, the sniper requested permission to shoot him, the newspaper said.
He was told to hold off.
Minutes later, an officer looking at images on the monitors inside the stadium's security room identified the man as a fellow police officer, who later was said to be investigating a suspected bomb threat. The man quickly left the area, the Folha de S. Paulo said.
Moneta said he would not comment on the reported bomb threat or on why the police officer was in the area where Rousseff and the others were sitting.