The Mirror says 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.
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 bench.
Arsenal did eject a fan following the flare-up after the visitors' second goal and have now contacted United for their findings.
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."