The World Anti-Doping Agency (WADA) accused cycling's world governing body of 'deceit' on Tuesday following its decision to disband its own independent commission into the Lance Armstrong drugs scandal.
WADA's damning criticism of the International Cycling Union (UCI) came as the independent commission itself issued a statement on Tuesday saying a lack of cooperation by the UCI and other interested parties had made its work "impossible".
Monday saw UCI president Pat McQuaid announce the closure of the independent commission after protracted argument about its powers and whether witnesses would be granted an amnesty protecting them from subsequent disciplinary action.
The commission had been created in response to allegations by the United States Anti-Doping Agency - whose inquiry led to Armstrong being stripped of his seven Tour de France titles - that cycling officials had been complicit in the American's cheating.
Irishman McQuaid, UCI president since 2005, said on Monday the commission was being scrapped in favour of a "truth and reconciliation process" (TRC), which had the support of WADA.
However, WADA president John Fahey denied this on Tuesday, accusing the UCI of being "determined to apparently deflect responsibility for the doping problem in its sport to others".
Fahey added: "UCI has publicly announced that WADA has agreed to work with it on some form of truth and reconciliation. This is not only wrong in content and process, but again deceitful."
Meanwhile a commission statement on Tuesday put pressure on McQuaid by saying: "Pat McQuaid stated that the UCI 'will cooperate fully with the commission'... and urged all other interested stakeholders to do the same.
"Neither the UCI nor interested stakeholders have provided sufficient co-operation to enable the commission to do its job.
"This failure to cooperate makes our task impossible."
"The UCI is perplexed that WADA has now chosen to rebuff and attack the UCI's willingness to establish a truth and reconciliation commission, having just demanded that the UCI establish exactly such a commission"
UCI president Pat McQuaid
But McQuaid, who said on Monday that WADA's refusal to take part had left the UCI with no choice but to scrap the commission, responded later on Tuesday by accusing Fahey of having a "personal vendetta" against cycling.
"Mr Fahey is saying one thing in public and quite the opposite in correspondence with me," McQuaid said.
"The UCI is perplexed that WADA has now chosen to rebuff and attack the UCI's willingness to establish a truth and reconciliation commission, having just demanded that the UCI establish exactly such a commission.
"We have now reached this sorry juncture because WADA publicly questioned the independence of the independent commission.
"I would therefore urge the president of WADA one more time to try to set his personal vendetta and crusade against cycling aside and to support the UCI in doing what is right for cycling.
"Our aims are the same: to rid cycling and indeed all sports of the scourge of doping."