In the 11 years since journalists and judges began looking into doping allegations against Lance Armstrong, all the inquiries have fallen down on two grounds: there has been no "smoking gun" and no copper-bottomed witness in spite of the weight of circumstantial evidence that has built up over the years. The allegations have always been emphatically denied and the denials have stuck.

Sparked by a federal inquiry into Armstrong's former team US Postal Service that goes back to last August, the events of the last two days have taken the Armstrong saga - and by extension the cycling world in which Armstrong remains an influential figure - into uncharted territory. They also provide possible insights into the direction of the inquiry, led by Geoff Novitzky, the man behind the Barry Bonds case.

On Thursday night, as part of the build-up to a showing of their investigative programme 60 Minutes, CBS released a segment of an interview with Armstrong's former team-mate Tyler Hamilton, in which the cyclist claimed that he had seen his ex-leader use the banned blood booster erythropoietin (EPO). Hamilton did not go into details, but if he can back up the claims, this would be a new and potentially devastating piece of evidence.

Read more at The Guardian ....