London: It is little surprise that Greg LeMond will not be rooting for Lance Armstrong on the Texan’s return to the Tour de France. They may be fellow civilians of the United States but there has been nothing civil about their recent exchanges, most of which have been conducted through lawyers.

Such is the level of antipathy that LeMond, the first American to win the race, in 1986, feels towards Armstrong that he cannot even bring himself to watch the event. “It’s painful because I loved the sport and I want to watch it, but if you know the truth ... I can’t do it any more,” he said.

LeMond looks like a man taking on the world. By gunning for Armstrong, who has come out of retirement to try for an eighth Tour victory, he effectively is. The cycling hegemony is behind Armstrong, who, despite LeMond’s past questioning of his achievements, has never failed a drugs test.

Few have invested so heavily in the anti-doping fight as LeMond, who estimates that he has spent up to $20 million (about £12.2million) on lawyers, not to mention the emotional toll.

“It’s cost my family a tremendous amount,” he said, after addressing Play the Game, a biennial conference on the ethical side of sport. “Imagine your son reading stuff about you on the internet that is false, calling you a thief and a bad person. They keep priming my pump but I’m more determined. There’s a subliminal pressure not to rock the boat, or you risk getting s*** upon.”

LeMond is also embroiled in a breach of contract suit with Trek International, which has a licensing agreement with LeMond Racing Cycles but also sponsors Armstrong, for whom he cannot hide his distaste.

“It’s kinda sad he can’t stay away from the limelight,” LeMond said. “He can come back and win eight or nine Tours but I’d rather have one of my victories than ten of his. I was fortunate to get into cycling when I did. If I had turned professional in 1993 or 1994, I don’t know what I would have done. This system corrupts everyone, even the good people.”

LeMond wants an independent anti-doping agency, separate from the UCI, the sport’s governing body, to test riders, but his feelings on the race are clear. “I don’t care about the future of the Tour unless it changes,” he said. “I’m done following it. I’m just riding my bike for fun.”