If found guilty of violent conduct Hleb would face a three-match ban – with Arsenal now only left with games against Derby, Everton and Sunderland to complete their season.

An FA spokesman said: “The first thing is to wait and see the referee’s report but that is not necessarily the end of the matter.”

The FA can call for video evidence from any match if they deem it necessary to apply justice to a clear offence which a referee has failed to punish.

The circumstances are certainly not without precedent as far as Arsenal are concerned.

Nearly 20 years ago their midfielder Paul Davis was banned for nine matches after TV footage showed him retaliating to verbal abuse with an off-the-ball punch which broke a Southampton player’s jaw during a match.

Although Hleb’s slap appeared to be only a comparatively minor contact, Arsenal’s former striker Jeremie Aliadiere was recently banned for four matches after appealing against a red card while playing for Middlesbrough having been sent off following a spat with Liverpool’s Javier Mascherano.

Alan Shearer, former England striker and BBC TV soccer pundit recalled the Aliadiere case in referring to Hleb and said: “I think the FA have to do something about this one, too.”

Reading manager Steve Coppell, who saw his side dragged deeper into the relegation fight with a 2-0 defeat at The Emirates, admits he does not understand the system by which players can be suspended for offences the referee has missed.

He said: “It is clear for all to see on the tape. I don’t think, in these circumstances, that anyone can say ’please, FA, look at it.’ I don’t know what the procedure is.

“It seems some mystery man phones in and says ’have a look at this piece of tape.’and then three other mystery men men make a decision on whether further action is required.

“The whole situation is unexplainable but maybe someone sitting in a front room will do something about it.”