Enlarge By Morne de Klerk, Getty Images Lance Armstrong, seen here signing autographs before Stage One of the 2011 Tour Down Under in Adelaide, Australia on Tuesday, was labeled in a Sports Illustrated story by a former teammate as "the instigator" for some team members to use EPO in 1995.

Sports Illustrated that the seven-time A 1995 teammate of Lance Armstrong says in a story in this week'sthat the seven-time Tour de France winner was "the instigator" for some team members to use EPO, a banned performance-enhancing drug that boosts the blood's ability to carry oxygen.

"It was his words that pushed us toward doing it," said New Zealander Stephen Swart, according to SI.com. U.S. federal agents began investigating doping in cycling last spring, after disgraced 2006 Tour de France winner and former Armstrong teammate Floyd Landis alleged that Armstrong was involved in organized doping.

On Tuesday, Armstrong's attorney Bryan Daly called the SI report an "attempt to cobble together some old stories to suggest that there is 'A case against Armstrong' or that an indictment is imminent."

In an e-mail to USA TODAY, Daly said allegations about Armstrong doping "are simply false and come from bitter and well known Armstrong adversaries who clearly lack credibility."

Wednesday morning, Armstrong repeatedly refused to comment on the report before saying he had perused it and "I have nothing to worry about on any level."

Johan Bruyneel, Armstrong's mentor and the manager of this Radio Shack team, also refused to discuss the report.

Armstrong spokesman Mark Fabiani calls the report "old news from the same old, discredited sources."

Daly also wrote that there "has been little or no investigative activity by the government for several months." Landis, whose title was stripped after he tested positive for synthetic testosterone, told ESPN.com on Monday that he is retiring from cycling.

The Associated Press contributed to this report.