The German Football Federation are investigating claims made by Mainz forward Aristide Bance that he was racially abused by an opponent.
The 25-year-old was pictured raising his middle finger to Frankfurt defender Maik Franz at the end of the Rhine-Main derby on Saturday after Frankfurt ran out 2-0 winners.
The DFB have confirmed that they will also ask Bance to explain his own actions as well as his claims made on German television afterwards.
Franz would almost certainly be punished if found guilty but the 28-year-old insists Bance has invented the whole saga in a bid to distract attention away from his own actions at the final whistle.
"It is absolutely ridiculous for him to claim that," Franz told Bild.
"Bance has put himself in the mire and he now wants to divert attention away from it. I have done nothing wrong."