LONDON - In the wake of fresh doping allegations against Lance Armstrong, cycling's world governing body and one of his former teammates came to the defense of the seven-time Tour de France champion on Monday.

Tyler Hamilton, another ex-teammate of Armstrong, said he witnessed the American take performance-enhancing drugs before or during the 1999, 2000, and 2001 Tours while with the U.S. Postal team.

However, team rider Viatcheslav Ekimov said he never saw Armstrong do any of the things Hamilton described.

The International Cycling Union also denied claims from Hamilton that it helped cover up a positive sample submitted by Armstrong at the Tour de Suisse in 2001.

"The UCI is deeply shocked by the seriousness of the allegations made on the 60 Minutes program aired by U.S. television network CBS," the organization said in a statement. "The allegations of Mr. Tyler Hamilton are completely unfounded."

Ekimov, who rode with Armstrong as a member of the U.S. Postal team and is now RadioShack's team manager, referred to Hamilton as a "liar" and suggested he has ulterior motives in making his revelations now.

"Behind his story is something," Ekimov said. "First of all, it's untrue. And behind his story is some money or some stimulation. Because why did this guy just crack now? Why didn't he do it in 2005? . . . I call these guys liars. First they lie about the innocence, now they lie about something else.

"I think it's just money. It seems to me like somebody really wants to kill Lance and put him down. There's all this interest to find people who will say something."

Hamilton twice has been banned for doping. Armstrong has denied doping and has never tested positive.

Hamilton said Armstrong told him of a positive sample he submitted in 2001, claiming the Texan made a deal with the UCI and they "figured out a way for it to go away."

But the UCI "categorically rejected" the accusation, insisting it had "never altered or hidden the results of a positive test." The organization also said Armstrong had never been notified of a positive finding.

"The UCI can only confirm that Lance Armstrong has never been notified of a positive test result by any anti-doping laboratory," the statement said. "Once again, the UCI wishes to state that no manipulation or cover up has occurred in respect of its anti-doping procedures."

60 Minutes also reported that UCI officials helped arrange a meeting involving Armstrong and the World Anti-Doping Agency-accredited laboratory at Lausanne which tested the Swiss race samples.

The UCI and its former president Hein Verbruggen, whose 14-year spell in office ended in 2005, denied such a meeting took place.

"There has never, ever been a cover-up. Not in the Tour de Suisse, not in the Tour de France," Verbruggen said. "I don't know anything about suspicious tests. I was not aware of that."

The UCI has said the 2001 Swiss race was clear of doping, and denied suggestions Armstrong gave it money for covering up a failed test.

Armstrong donated $25,000 in 2002 for the Swiss-based organization's anti-doping program and $100,000 in 2005 for the purchase of a Sysmex machine used for analyzing blood.

Hamilton's claim regarding the Tour de Suisse was previously made by Lancaster County native Floyd Landis, another rider who denied doping during his career before later admitting to using banned substances.

Verbruggen and his successor as UCI president, Pat McQuaid, are suing Landis in a Swiss court for saying the governing body protected star riders from doping allegations.

In a separate development on Monday, Italian police carried out a search on the hotel of the RadioShack team currently competing in the Giro d'Italia. The RadioShack team is backed by Armstrong.