California: Seven-times Tour de France winner Lance Armstrong has dismissed claims by former team mate Floyd Landis that he used performance-enhancing drugs.
Landis, who was stripped of his 2006 Tour victory after a positive test for testosterone, has confessed to using performance-enhancing drugs and accused others, including Armstrong, of doping.
"We have nothing to hide. We have nothing to run from," Armstrong, who was Landis`s team leader at US Postal, told reporters before crashing out of fifth stage of the Tour of California.
"(The allegations) they`re not even worth getting in to. I`m not going to waste your time or my time. I think history speaks for itself here. We`ve all followed this case (Landis) for the last four years."
Armstrong, who was taken to hospital after a heavy fall early in Thursday`s stage, said Landis, had no credibility.
"This is a man that`s been under oath several times and had a very different version," Armstrong said.
"This is man that wrote a book for profit that had a completely different version. This is somebody that that took, someone said close to a million dollars, from innocent people for his defence under a different premise.
"And now when it`s all run out, the story changes. So we`re a little confused."
Armstrong has had to fend off accusations of doping before but has never failed a drugs test and always denied taking banned substances.
"It`s our word against his word," Armstrong said. "I like our word. We like our credibility. Floyd lost his credibility a long time ago."
A survivor of testicular cancer, Armstrong won the Tour de France a record seven times between 1999 and 2005 before retiring.
He made a comeback last year at the age of 37, finishing third in the Tour, and is aiming for an eighth win this year after forming his own team, RadioShack.