Lance Armstrong and Team Radio Shack are formally denouncing allegations by former colleague Floyd Landis that the cyclist once indulged in performance-enhancing drugs.

In a statement released on the Team Radio Shack website, the group called Landis' statements "false and incredible concoctions" that, according to the group, the athlete had been known to make in private over the past four years.

The group says Landis grew frustrated when he learned that he was unable to compete in the Tour of California this year and threatened to tell the public Armstrong used performance-enhancing drugs.

"I'm going to accuse you and our former team mates of using blood doping and performance enhancing drugs to help you to win the three Tours de France in which we raced together," Landis allegedly wrote in an e-mail to Armstrong and event organizers.

Armstrong denied the allegations just before Stage 5 of the Tour of California, stating it was "our word against his" and that he "liked our word better."

Armstrong was pulled from Stage 5 after getting involved in a massive wreck in-between Visalia and Bakersfield. The cyclist was taken to the hospital for X-Rays, which later revealed no fractures.