Attorneys for Texan Lance Armstrong -- who denies doping -- have demanded an on-air apology from the CBS program "60 Minutes" about a show that aired last month.
Lawyer Elliot Peters says the May 22 segment about Armstrong -- who lives in Austin -- was built on falsehoods.
The head of Switzerland's anti-doping lab denies that the seven-time Tour de France winner tested positive for performance-enhancing drugs at the 2001 Tour de Suisse.
CBS News spokesman Kevin Tedesco declined comment on the letter seeking an apology, but says: "We consider this the most thorough investigation into doping in the sport of cycling ever done."
Ex-teammate Tyler Hamilton alleges Armstrong talked about using a banned blood booster to prepare for his third Tour.