Olympic goal medalist Tyler Hamilton, seen here during the 2009 Tour of California, has leveled the most serious doping allegations against Lance Armstrong to date.

Cycling champion Lance Armstrong has long denied ingesting performance-enhancing drugs and engaging in blood doping, but allegations from a former teammate suggest that not only did Armstrong lie and cheat his way to seven Tour de France titles, but that a larger conspiracy covered up a positive 2001 drug test and that widespread cheating on Armstrong’s team was the norm.

American Tyler Hamilton, a former teammate of Armstrong’s who also won the cycling gold medal at the 2004 Summer Olympics in Athens, told 60 Minutes, in a segment that aired Sunday night, that he personally saw Armstrong inject performance-enhancing drugs, including the synthetic steroid known as EPO, during the 1999 Tour de France and in the run-up to both the 2000 and 2001 Tours de France. Beyond that, Hamilton suggested US Postal Service Racing officials helped supply cyclists with drugs as well as advise them on how to beat international tests.

Armstrong’s defense for years has been that he is the most tested athlete in sports history and that he has passed every one of them, hundreds over the last 20 years. However, Hamilton said that Armstrong personally told him that a positive drug test at the 2001 Tour de Suisse was covered up, claims that disgraced rider Floyd Landis, another former teammate of Armstrong’s, has also made in the past. (Armstrong insists there has been no coverup.)

Hamilton came forward now because a subpoena recently compelled him to testify before a Los Angeles grand jury that has been investigating Armstrong. Years ago, Armstrong’s team secured the US Postal Service — and millions of dollars in sponsorship money from the federal government — in part by promising that he and his teammates were clean. So if he knowingly lied to the US government, that could be something prosecutors might be interested to know, as well as possible drug trafficking (Hamilton says Armstrong facilitated the speedy delivery of EPO on at least one occasion) and fraud.

With a new blog unveiled late last week called Facts4Lance.com, Armstrong has set up a one-stop shop to counter allegations both present and past, providing links to documentation that he claims is exculpatory while also attacking the credibility of those who claim he has doped in the past.

EPO is a naturally occurring hormone that is produced in the liver and kidneys that helps regulate the production of red blood cells, full of the oxygen that elite athletes so often crave. But EPO has been manufactured in a synthetic form since 1989, and a well-timed dose can supply a worn-down athlete with a quick boost to his muscles and stamina. (Of course, EPO can also thicken the blood, leading to blood clots, strokes, heart attacks, and even death.)

The allegations from Hamilton marked a dramatic shift in the nature of the criticism leveled toward Armstrong. Normally, the sources of these are French tabloids or zealous international doping officials or already disgraced former champions. That these supposed revelations are now coming from the well-respected, usually reticent Marblehead, Massachusetts, native could signal one of the final blows in Armstrong’s enduring legacy.

Barring some incredible admission from Armstrong himself, the last straw may come from federal grand jury testimony given by cyclist George Hincapie, a teammate of Armstrong’s on all seven Tour de France-winning teams. 60 Minutes says that Hincapie has testified that he and Armstrong both used EPO and “discussed having used testosterone, another banned substance, during their preparation for races.”

Rather than issue a flat-out denial, Hincapie took to his Twitter account to address the 60 Minutes report. “I can confirm to you I never spoke with ‘60 Minutes.’ I have no idea where they got their information,” he tweeted on Friday. “As I’ve said in the past, I continue to be disappointed that people are talking about the past in cycling instead of the future.

“As for the substance of anything in the ‘60 Minutes’ story, I cannot comment on anything relating to the ongoing investigation.”

With these accusations following a months-long investigation into 2010 Tour de France winner Alberto Contador and whether his ingestion of a tainted filet mignon triggered a failed drug test — he was ultimately cleared of wrongdoing — professional cycling may be on the verge of a tipping point, where the code of silence among elite riders means less than it ever has and where the moral imperative to clean up the sport finally trumps all other considerations.

Short of that, the sport will never truly be considered clean and irreparable harm may have already taken hold of cycling’s core.

Photo: Flickr/joe_mac_1, CC