"The military police of the state of Rondonia has already initiated an internal investigation into possible irregularities committed in that incident," police spokesman Lenilson Guedes told Reuters on Friday.
"We have already asked for local TV footage so we can analyse the images."
The dismissals occurred in the 64th minute when Genus, who played in last year's Brazilian championship fourth-tier Serie D, were losing 3-0 to Moto Esporte Clube in one of the country's minor state championships.
"The players refused to go off (and) insulted the referee so he called the police who were on duty in the stadium to guarantee security (for the match officials)," Guedes said.
"Players are believed to have sworn at the police officers and one sprayed them."
In such incidents "the first approach must be oral, 'citizen, kindly leave the place', then they can be escorted out by the arm, the third stage would be to use a truncheon and the fourth the spray.
"This officer passed directly to the spray," said Guedes.
