A number of decisions appear to have gone against the Nerazzurri in recent weeks which has led to the ex-Italy international to speak out.
"I do not believe in bad faith, I believe that the referees are scared, they show it Sunday after Sunday,” he told reporters.
"Against Juve, a penalty was not given on [Antonio] Cassano, then a penalty was given to Atalanta. On Sunday a penalty was not given to [Cagliari's Victor] Ibarbo and instead one was given to [Mauricio] Pinilla that was not there. These are strange things."
Materazzi added referees cannot be the sole blame for the poor season suffered by Inter, with the team’s defence being an issue.
"If a team concedes 45 goals in a year is something wrong there."
Inter will face Roma in the Italian cup semi-final and the World Cup winner believes victory in that tournament could salvage something from this season.
He added: "This is a decisive game, especially since there is little they can do in the league. Our journey began long ago with an Italian Cup; I hope that it will end in victory."