The nasty tug of war between the bosses of the international cycling union and the World Anti-Doping Agency over who leaked documents to a French newspaper accusing Lance Armstrong (search) of doping claimed its first casualty Thursday: any chance of a comeback by the seven-time Tour de France champion.

Armstrong, who said just days ago that this latest fight to clear his name had stoked his competitive desires, made clear Thursday he wasn't interested in returning to the sport he dominated.

"Sitting here today, dealing with all this stuff again, knowing if I were to go back, there's no way I could get a fair shake — on the roadside, in doping control, or the labs," Armstrong said on a late-afternoon conference call.

"I think it's better that way," he added a moment later. "I'm happy with the way my career went and ended and I'm not coming back."

Armstrong and his handlers spent most of the remaining 45 minutes with reporters criticizing WADA chief Dick Pound (search). It was Pound who set off another round of charges and counter-charges in the doping controversy earlier Thursday by accusing cycling union boss Hein Verbruggen (search) of supplying documents used by L'Equipe, France's leading sports daily, to charge that Armstrong used the blood-boosting drug EPO during his first tour win in 1999.

Armstrong, who has repeatedly denied ever using banned drugs, said he was the victim of a "witch hunt" after the report came out last month.

Arsmtrong said he was concerned Pound might be seeking revenge for an open letter he sent to newspapers and the WADA chief several years ago, defending his sport against the widely held notion that cycling was rife with competitors using performance-enhancing drugs.

"I was not trying to say that Dick was bad guy or a crook," Armstrong said of his letter, "but I might want to say that today. ... He's trying to divert attention from the serious ethical issues involving WADA and himself."

His agent and attorney went even further, accusing Pound of smearing Armstrong in public without conclusive proof or due process. They also said Pound had a hand in ensuring that an identifying code was included with the results of tests for EPO conducted by a French lab on Armstrong's urine samples six years after they were taken. If true, that would violate WADA's own protocol requiring that any tests be done strictly for purposes of research.

Calls seeking comment from Pound at both his WADA office and home in Montreal were not immediately returned Thursday.

Earlier Thursday, Pound said he received a letter from Verbruggen ackowledging the cycling union, known as UCI, had provided L'Equipe's reporter with forms indicating Armstrong had tested positive for EPO during his first Tour victory.

"Mr. Verbruggen told us that he showed all the forms of Mr. Armstrong to L'Equipe and that he even gave the journalist a copy of one of the documents," Pound said during a conference call from Montreal.

"I don't understand why they're not stepping up to that and saying, 'Well, I guess we do know how the name got public, we made it possible,"' he said.

But Armstrong said that he himself had authorized releasing the forms to L'Equipe. He said the request from the newspaper was to check whether the UCI had granted him any medical exemptions during competition, not to find out if the numerical code used by race official to identify Armstrong matched the one attached to the frozen samples.

Last Friday, the UCI said it had not received enough information to make a judgment on the accusations that six of Armstrong's frozen urine samples from 1999 came back positive for EPO when they were retested last year.

It also criticized L'Equipe for targeting Armstrong and Pound for making public statements on the "likely guilt of the athlete" without knowing all the facts.

Pound countered by saying, "It's .... quite clear the only way there could have been a match between the code numbers and a particular athlete was on the basis of information supplied by the UCI."

He then questioned the UCI's willingness to fully investigate L'Equipe's accusations and wondered whether the cycling body was merely looking for a "scapegoat."

If so, Armstrong suggested Pound should look in a mirror.

"Is Dick Pound a vindictive person and somebdy who holds grudges?" he said. "Perhaps."

Armstrong again refused to rule out legal action against L'Equipe. And while he said again he wouldn't make a comeback next summer, it's not because of a lack of competitive desire.

Asked whether rumors that President Bush beat him in a bike race during a visit to Crawford, Texas, several weeks ago, Armstrong replied, "no," but insisted the president was a strong rider.

"But we didn't subject him to any medical controls, so we don't know if his performance was enhanced. In my opinion," he added, laughing, "it was suspicious."