His rant on Tuesday, which has shocked people in Italy not yet fully used to the Portuguese's outspoken style, followed a row over a contested penalty in Sunday's 3-3 draw with AS Roma.
Inter striker Mario Balotelli was accused of diving by Roma midfielder Daniele De Rossi and all three are now in trouble.
"Following an investigation by the federal prosecutor, action over the behaviour and declarations of Balotelli, De Rossi and Mourinho will be announced tomorrow," the Italian football federation said in a statement on Wednesday.
Mourinho, named Inter coach in June, said his rivals had manipulated public opinion against the league leaders and that second-placed Juventus had benefited from refereeing mistakes.
Juve, demoted in a match-fixing scandal in 2006, reacted furiously to Mourinho's comments and the former Chelsea coach could now face a touchline ban.
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