MIAMI (AP) -- Disgraced U.S. cyclist Floyd Landis revealed new cheating allegations in a series of messages to sponsors and officials, alleging that former teammate Lance Armstrong not only joined him in doping but taught others how to beat the system and paid an official to keep a failed test quiet.
Landis admitted for the first time what had long been suspected -- that he was guilty of doping for several years before being stripped of his 2006 Tour de France title.
His fresh accusations, contained in e-mails sent last month, prompted Armstrong to hold an impromptu press conference on Thursday before he began the fifth stage of the Tour of California in Visalia.
"If you said, 'Give me one word to sum this all up,' credibility," the seven-time Tour de France winner said. "Floyd lost his credibility a long time ago.
"We have nothing to hide. We have nothing to run from," said Armstrong, who later quit the race after crashing just outside of Visalia, California. Team spokesman Philippe Maertens told The Associated Press that Armstrong got stitches in the left elbow and under the left eye.
Though Landis lost his title, he denied cheating until now, and his recent e-mails detail his blood doping.
"I want to clear my conscience," Landis told ESPN.com. "I don't want to be part of the problem any more."
He claims that Armstrong and longtime coach Johan Bruyneel paid an International Cycling Union official to cover-up a test in 2002 after Armstrong purportedly tested positive for the blood-boosting drug EPO. The UCI, however, denied changing or concealing a positive test result.
