Manchester United security staff have been accused of sparking crowd problems during their clash with Arsenal.
Witnesses have reported a United security official for allegedly goading Arsenal fans following the visitors' second goal during the 2-2 draw at the Emirates.
Arsenal have contacted Manchester United for their version of events after their security officer refused to cooperate.
But Ferguson has upset Arsenal with his claims that there were problems in the crowd directly behind the dug-out.
The Scot claimed after the game that there was "disgraceful abuse" aimed at his staff, "a lack of security" and there was an "absolute danger" to the United bench.
A United spokesman said: "The priority of our security staff at all times is to protect the players and the staff on the bench.
"It is nonsense to suggest there was any goading from our staff, as Arsenal confirmed after the game."