IT'S a story that seemed destined to rumble on forever.

Each time the dissenters voiced their disbelief that Lance Armstrong's phenomenal cycling career could have been achieved by anything but disreputable methods, the man himself would deny it fervently.

Now, it appears, it may come to a head once and for all. The US Anti-Doping Agency (USADA) has formally charged Armstrong and five associates at his former US Postal Service team over alleged doping violations.

Armstrong has been banned from competition with immediate effect, including from the triathlons and iron man events he has been contesting since his second retirement from professional cycling last year.

The USADA charges are not criminal, but the agency can ban athletes and revoke titles which ultimately means Armstrong could be stripped of his record seven Tour de France victories.

The Texan-born rider has spent almost a dozen years fighting allegations of doping, but this will be his biggest – and most significant – battle yet.

The USADA statement said: "In response to numerous inquiries regarding the public statements made by Mr Lance Armstrong, we can confirm that written notice of allegations of anti-doping rule violations was sent yesterday to him and to five additional individuals all formerly associated with the United States Postal Service (USPS) professional cycling team. These individuals include three team doctors and two team officials. This formal notice letter is the first step in the multi-step legal process for alleged sport anti-doping rule violations."

Armstrong hit back with a statement on his website which reiterated his innocence and expressed outrage, labelling the accusations by USADA "baseless" and "motivated by spite".

He said: "I have never doped and, unlike many of my accusers, I have competed as an endurance athlete for 25 years with no spike in performance, passed more than 500 drug tests and never failed one. That USADA ignores this fundamental distinction and charges me instead of the admitted dopers says far more about USADA, its lack of fairness and this vendetta than it does about my guilt or innocence."

Yet there is more at stake than simply whether or not Armstrong will hold on to his cycling legacy. He is, after all, the world's most famous cancer survivor, a man who has inspired millions around the globe in their battle with the disease.

Diagnosed with testicular cancer in 1996 he was given, at one point, as little as a 3% chance of survival. While still undergoing treatment for the disease, he founded the Lance Armstrong Foundation known as Livestrong.

Since its inception, the organisation has raised $450m to fund cancer research, with more than 80 million of its trademark yellow silicone bracelets having been sold worldwide to date.

Armstrong's mantra "pain is temporary; quitting lasts forever" is just as famous; it has been adopted by countless supporters and emblazoned on everything from T-shirts to tattoos.

For many, the man who battled cancer and went on to inspire the masses with his sporting triumphs is one entity, while the man who may – or may not – have been involved in what is described as "fully consistent with blood manipulation including EPO [erythropoietin] use and/or blood transfusions", according to allegations in the 15-page USADA report is another entirely. Yet, the two are not intrinsically inseparable. If the latter proves to be true then the former, undoubtedly, will ring a little hollow.

To date, all previous investigations into Armstrong's alleged doping – from a French prosecutor's probe in 2000 to the US Federal government inquiry headed by the Food and Drug Agency earlier this year – have eventually been dropped or abandoned.

Whether Armstrong emerges this time with halo intact or exposed as a brass-necked drugs cheat, certainly, interesting times lie ahead. The burning questions are this: did he dope? And – more controversially – does it matter? While the gut instinct to the latter is a 'yes', taking a step back to view things casts the matter in an entirely different light.

Is the USADA advocating that, in turn, all victories where doping is alleged be retrospectively revoked in an era of cycling where cheating was rife? Titles can be stripped and passed on, but who is to say the next man in line is any more worthy?

In an interview with Herald Sport last year, the Scottish cyclist David Millar, banned from professional cycling between 2004 and 2006 after admitting to taking the banned blood boosting hormone EPO, talked about the overwhelming sense of relief which came after French police found the empty phials and syringes he had kept as "a poignant souvenir".

"If the syringes hadn't been there, I would probably have fought and denied [the doping allegations]," said Millar. "I would likely have ended up being released from the police investigation, but then having to live the lie forever. It would have then been a downward spiral to destruction."

For Armstrong – if he has doped – surely living with that colossal burden of truth will be the greatest punishment of all.