The Football Association has confirmed it will look into claims that Marouane Fellaini spat at Pablo Zabaleta during the Manchester derby on Tuesday.
Footage on YouTube has emerged appearing to show Manchester United midfielder Fellaini spitting near to Zabaleta's head while the City defender lay on the floor following a clash between the pair.
The FA is aware of the clip and is now considering whether it should charge Fellaini for misconduct.
It is reported by the Press Association that referee Michael Oliver did not mention the alleged incident in his match report, but the FA can retrospectively punish Fellaini if it finds him guilty.
The FA will request clearer footage of the incident from broadcasters Sky before making a decision on the matter early next week.
The FA banned Hull's George Boyd for three matches after he spat at Manchester City goalkeeper Joe Hart earlier this month.
Oliver booked Fellaini moments before the alleged incident towards Zabaleta for an elbow on the Argentine full-back.
After the 3-0 win, Zabaleta claimed Fellaini was lucky to stay on the pitch. “I was elbowed by Fellaini. It was a red card,” he said.