Hamilton has just published a tell-all book called "The Secret Race" about the years he spent as friend and colleague of the seven-time Tour de France winner - a book which he says has made him feel "fantastic" as he has finally got the details off his chest.
"I denied it for years," Hamilton said. "After a while you get pretty good at it. I lied for a long, long time. There was sort of an omertà. People really encouraged me not to speak.
"I planned to take this secret to the grave."
Hamilton did not do so, however, after being subpoenaed by a Grand Jury investigation in the US two years ago. Knowing that if he had lied he could face perjury charges, he spoke out despite receiving a personal threat from Armstrong.
"When you're on the witness stand, we are going to f***ing tear you apart," Hamilton claims Armstrong told him. "You are going to look like a f***ing idiot. I'm going to make your life a living f***ing hell."
That threat, Hamilton claims, only came after he had refused Armstrong's offer of free legal help.
"My lawyer was receiving a series of urgent calls from Lance's lawyers, who were offering me their services, for free," Hamilton writes in his new book.
"It was a classic Lance move. For six years, he gives me zero support. Now, when things get tough, he wants us on the same team again. No thanks."
Armstrong denies doping, but has declined to contest the US Anti-Doping Authority's charges.
The seven-time Tour de France champion has also received backing from 23 Californian state senators, who are requesting a congressional review of USADA's decision to ban Armstrong for life from competition.
Asked Wednesday by phone what he felt was the biggest myth exploded in "The Secret Race," Hamilton told Yahoo! Sports: "That only a few bad eggs were doping. Every rider I knew – knew well enough – [doped]. It was a choice that most young professional riders had to make a decision on, including me."
Hamilton isn't shy about that point, either in the book or over the phone. "It starts with just a small red pill," he explains. "Then a shot of EPO. Then the next year you do a little bit more. Then it becomes a part of your routine. Then they expect you to go to the best doctors; they expect you to be flying on all cylinders. It's a tough spot to be in."
One of the many eyebrow-raising passages in "The Secret Race" is when Armstrong is said to have conversed with leaders of the sport after an alleged failed drug test during the 2001 Tour of Switzerland. In the book Hamilton implies that the cycling hierarchy helped Armstrong get away with something.
Lance had a strange smile on his face. He was kind of chuckling, like someone had told him a good joke.
"You won't [expletive] believe this," he said. "I got popped for EPO."
It took me a second to absorb. My stomach hit the floor. If that was true, Lance was done. The team was done. I was done. He laughed that dry laugh again.
"No worries dude. We're gonna have a meeting with them. It's all taken care of."
Hamilton does more than hint that cycling had all the incentive in the world for Armstrong to keep clean and keep winning. He writes simply: "The UCI didn't want to catch Lance."
Hamilton doesn't exactly gloat about his findings. He calls the book "a sad story" and, when asked if he would have pursued cycling if he knew at the start of his career what he knows now, he says, "I don't think so." He insists he wants very much to help clean up the sport, but he quietly offers an anecdote about when he asked his 10-year-old nephew what he wanted to be when he grows up. The boy told Hamilton he wanted to be a cyclist.
"That made me feel sick," he says.
One would think reading this book would make Armstrong's supporters feel sick, too. But don't expect many minds to change.
Armstrong's detractors will point to this book as the ultimate prosecution of cycling's greatest American hero. In fact, you can expect many to conclude Armstrong recently dropped his fight with anti-doping authorities because a mountain of witness "evidence" like this was about to surface. And Hamilton enlists more than a few credible witnesses to take the stand in this book – team-mates, rivals, friends.
The result is overwhelming: testimony not only about when and how the alleged doping was done, but how many layers it took. "It was sort of a Russian doll," says co-author Dan Coyle, also interviewed by phone on Wednesday. "Compartments and compartments and compartments. At the end of the day, though, all the stuff is happening behind closed doors. It was a community of secrets."
"If you were careful and paid attention," writes Hamilton, "you could dope and be 99 percent certain that you would not get caught."
In other words, although the subterfuge reads like a screenplay for an episode of "24," evading the drug police wasn't all that difficult. In one of the more clandestine anecdotes, Hamilton writes that a courier nicknamed "Motoman" would ride up to Armstrong with prepaid cell phones and thermoses of EPO.
So the most significant aspect from Hamilton's work is not that he has evidence Armstrong doped but rather it's the undermining of Armstrong's famous PR crutch, namely that he never failed a drug test.
Hamilton has a quote from a doctor insisting that "the winner in a doped race is not the one who trained the hardest, but the one who trained the hardest and whose physiology responded best to the drugs."
And then, it's Hamilton himself who writes, "Once you get past a one-week race, it quickly becomes impossible for clean riders to compete with riders using [EPO], because [EPO] is too big an advantage. The longer the race, the bigger the advantage becomes – hence the power of [EPO] in the Tour de France."