Thousands of Liverpool fans are gathering in Athens to see their team take on AC Milan in tonight's Champions League final.British police advising the Greek authorities believe around 25,000 Reds fans will be at the match, despite each finalist only being handed an allocation of 17,000 for the Olympic Stadium.Liverpool, however, believe that as many as 40,000 fans could be able to gain entry to the 63,000-capacity stadium as they look to be crowned champions of Europe for the sixth time.Some supporters looking to pick up tickets have revealed that they have been asked to pay between 400 euros and 2,000 euros (£270-£1,360) on the black market to secure their seat in the ground.Clive Cook, 38, from Worcester, who is a football coach in the US, said: "I've bought one for 400 euros but am a little worried in case it is a forgery."I don't think they should have these events in grounds with a capacity under 80,000, especially when they give us only 17,000 tickets."In the build-up to the game, Reds fans have been partying in Syntagma Square, in the city centre and have been savouring the atmosphere ahead of the biggest showpiece in European club football.The British Embassy said staff had distributed 10,000 leaflets giving advice on what to do if fans encountered a problem, and estimated there could be 12,000 supporters in town already.There are due to be 8,500 police officers in and around the stadium and the city for the match.And Chief Superintendent Dave Lewis, of Merseyside Police, leading the British operation to assist the Greeks, said: "If I had over 8,000 officers, I would be confident of handling just about anything."Two years ago Liverpool produced one of the greatest comebacks ever, overturning a three-goal deficit in Istanbul, to beat AC Milan on penalties to win the Champions League.© Independent Television News Limited 2007. All rights reserved.