UEFA has moved to increase the punishment imposed on PSV Eindhoven for their fans' racist abuse of Arsenal players in the Champions League last month.

European football's governing body has taken the highly unusual step of appealing against a decision made by its own semi-independent disciplinary panel.

A £13,000 fine had originally been imposed despite the Dutch club having a track record of racist and violent crowds. However, that sanction looks to have been deemed insufficient.

Gerhard Aigner, UEFA's chief executive, will now ask Arsenal to provide written evidence of the racist abuse - which has been mentioned by both Thierry Henry and Ashley Cole - and will appoint a disciplinary inspector to hold an appeal hearing.

Aigner said in a statement: "The control and disciplinary body has to be allowed to look at each case referred to it and make a decision on the available evidence.

"However, if there's reason to believe that the verdict is not wholly appropriate or that further evidence needs examination then I can intervene.

"In this instance I will now appoint a disciplinary inspector to prepare fort he appeal hearing and we would ask that all of the parties concerned provide written evidence - statements to the media are not enough - we need hard evidence to move forward not just public declarations."

The decision means PSV could yet be forced to play a match behind closed doors as punishment. It also highlight's UEFA's intent to take a firm stand against racism following several incidents in European games, most recently the shocking abuse by Slovakia fans of England's black players at the weekend.