During the closing stages, with the tie already lost, Nicklas Bendtner – who had earlier scored an own goal – became involved in an altercation with team-mate Emmanuel Adebayor, and appeared to complain of being headbutted by the Togo international.

Arsenal captain William Gallas stepped in to try to calm matters down, before then himself being confronted by the angry young Danish striker. Eventually, referee Webb had to intervene to restore order.

As the Yorkshire official revealed he did not witness the events in their entirety, the FA have now asked broadcasters to provide any relevant television footage.

Once that is obtained, any incidents will be shown to Webb for his opinion.

Should the referee indicate action would have been taken on the night had he witnessed it first hand, such as a red card for violent conduct, the FA can then retrospectively issue charges against any individuals.

While still photographs in today’s press clearly show the Arsenal players involved in some sort of confrontation, it is understood there may not be any footage of the actual alleged headbutt itself.

Arsenal manager Arsene Wenger maintained he was not aware of the incident, while captain Gallas refused to single out anyone for blame.

The France defender said: “I don’t know what happened. I think everybody was disappointed with the score and they were nervous.

“They know they made a mistake. Maybe they will speak with the boss to see why they did that.”

Gallas added: “We lost our calm. Sometimes it is difficult to be calm and it is not easy for some players to be calm. We were too nervous. We have to learn.”