NICOSIA, Sept 20 (Reuters) - The battle against match-fixing is being undermined by a lack of sufficient evidence which often leads to the abandonment of investigations, a European sports forum was told on Thursday. In a declaration adopted in Cyprus, EU sports ministers and representatives of European sport called for "effective and sustained action" to nip match-fixing in the bud. But proving a link between fraud and the deliberate under-performance of players is not always easy despite mechanisms brought it to try to combat the problem. ... More...