Embattled Tour de France icon Lance Armstrong Wednesday angrily brushed off fresh doping allegations that emerged in a magazine report.
Armstrong is the subject of a federal investigation in the United States following allegations of doping levelled by disgraced former teammate Floyd Landis, who was stripped of his 2006 Tour de France title for doping.
A fresh report claims to substantiate Landis's accusations.
American magazine Sports Illustrated made several allegations against Armstrong in a website report Tuesday, including one that said Armstrong once used a hard-to-detect blood boosting drug, HemAssist, to boost his performances in the late 1990s.
Armstrong successfully battled cancer in 1998 and returned to the sport to win the world's biggest cycle race seven times.
The American, who is set to retire after the Tour Down Under this week, brushed off the fresh doping claims before the start of the race's second stage Wednesday.
"I don't have anything to say," he said when asked by AFP to respond to the report, which he said he had read. "I've perused it. There's nothing there."
In 2010, Landis launched a series of damning allegations against Armstrong, with whom he rode in the US Postal team for several years, claiming the American had used banned substances throughout his career.
Armstrong has never tested positive and has rejected all allegations of doping. He also claims Landis is not a reliable witness because he has confessed to being a drugs cheat.
Landis attempted a recent comeback to the sport but on Tuesday announced his retirement, claiming doping was still widespread and would be nearly impossible to eradicate.
On Landis's decision to retire, Armstrong added: "Got nothing to say about that either."
When pressed on Sports Illustrated's claims, he hit back: "Dude, are you that stupid? Which part of 'I'm not commenting' is not clear to you?"
Armstrong added: "I don't have anything to worry about on any level."
The Sports Illustrated report claimed it had "new information" about Armstrong, having "reviewed hundreds of pages of documents and interviewed dozens of sources in Europe, New Zealand and the US".
The report cited another former member of Armstrong's old team, Motorola, New Zealander Stephen Swart, who told the magazine the Texan was the driving force behind some of the team members deciding to use the banned blood booster EPO (erythropoietin) in 1995.
"He was the instigator," Swart is quoted as saying in the report.
"It was his words that pushed us toward doing it."
Sports Illustrated posted some of its findings on its website Tuesday and said it expects to include a longer version of the story in the January 24 issue of the magazine.
Swart is not the only former Armstrong teammate to admit using performance-enhancing drugs and made similar accusations against Armstrong in a 2004 book L.A. Confidentiel - Les secrets de Lance Armstrong.
He described to Sports Illustrated a regular hotel-room scene where riders pricked their fingers to draw blood and then tested it for hematocrit levels. Riders were given a 15-day ban if their hematocrit level surpassed a reading of 50.
On one occasion his reading came back at 48 and Armstrong's was "54 or 56", he said.
Armstrong is the focus of a criminal probe headed by Jeff Novitzky of the US government's The Food and Drug Administration which is looking into whether Armstrong was involved in an organized effort to illegally use performance-enhancing drugs.
Among the others issues raised by Sports Illustrated Tuesday is the credibility of a drug-testing lab at the University of California Los Angeles (UCLA) run by anti-doping guru Don Catlin.
In 1999, USA Cycling asked Catlin to retest some of Armstrong's alleged samples.
The samples were stored, not by name, but with a drug-testing code number on them. Sports Illustrated says one of its sources told them the samples belonged to Armstrong.
The lab could not find five of the testosterone-epitestosterone test results USA Cycling had asked for but three others did "stand out", Sports Illustrated reported.
One of the results had a ratio of 9.0-to-1 and another was 7.6-to-1. Anything above 6.0-to-1 was considered abnormal at the time. A normal person has a ratio of 1-to-1.
Sports Illustrated reported that after retesting the samples, Catlin wrote back "the confirmation was unsuccessful and the samples were reported negative."
Sports Illustrated did not say whether it contacted Catlin for a reaction.
Another former teammate and Armstrong critic, Floyd Landis, also claims in the article that they were once stopped in 2003 at an airport in Saint Moritz, Switzerland where customs officials searched one of Armstrong's bags and discovered syringes and drugs used for doping.
Landis, who has also admitted using performance-enhancing drugs, said Armstrong was let go after a teammate convinced officers the items in the bag were vitamins and the syringes were used to inject the vitamins.
Frankie Andreu, who rode on the United States Postal Service team with Armstrong, has also admitted using performance-enhancing drugs.
Armstrong is widely credited with one of the greatest comebacks in the world of sport and his Livestrong foundation - which raises money and awareness in the global fight against cancer - is followed by millions.
© AFP 2011