Arsenal's Edu has admitted there was an altercation between Manchester United and Gunners players after last Sunday's Old Trafford encounter.
The current champions' 49-game unbeaten Premiership run came to an abrupt end amid controversial circumstances.
Afterwards, it was being reported that Alex Ferguson had soup and pizza thrown at him by a member of the Arsenal squad who remains unidentified.
The FA are trying to establish what happened and, although Arsene Wenger insisted nothing happened, Edu has seemingly contradicted his manager.
He told www.uefa.com: "Afterwards, as we went down the tunnel, I saw people being pulled apart, people pushing, pointing and shouting.
"The United players were shouting at us and trying to wind us up about the result. But I didn't see any soup being thrown at anyone.
"To be honest, there was nothing that I haven't seen in the Brazilian derbies. Derby matches in Brazil are worse. I like to play in games like this with this intense rivalry."
