Rival International Cycling Union presidential candidates Pat McQuaid and Brian Cookson have both issued strongly-worded statements following the emergence of an anonymous leaked dossier alleging corruption at the UCI.
British Cycling president Cookson is challenging current UCI president McQuaid in an increasingly acrimonious election contest, which is still in dispute after McQuaid failed to secure a nomination from either Ireland - his home country - or Switzerland, his current place of residence.
McQuaid now wants the UCI Congress to vote in a rule change to allow him to be nominated by Thailand and Morocco and a number of federations, including the United States, have asked for the UCI to take the dispute to the court of arbitration for sport for a decision on whether that should be permitted.
McQuaid issued a statement in response to the corruption allegations.
He said: "On Monday evening, a cycling website was anonymously leaked a libellous 'dossier', alleging corruption at the UCI.
"The claims in this so-called dossier are a complete fabrication. They are totally untrue and are not supported by a scintilla of evidence."
"This is a scurrilous and libellous attack on my character." - Pat McQuaid comments on anonymous dossier
"The UCI Ethics Commission have already tried to investigate the matter.
"This is a scurrilous and libellous attack on my character."
Cookson called for a new investigation to be launched. He said in a statement: "These allegations, which appear to be similar to those made to the UCI Management Committee in June, are clearly very serious.
"For the good of the UCI and cycling, they should be immediately and thoroughly investigated by the relevant authorities. I hope that this matter can be fully resolved before the UCI congress on 27 September."
The UCI Congress will elect the world governing body's next president at the World Road Championships on September 27 in Florence, Italy.