Former cycling doper turned whistleblower Tyler Hamilton described Dr Eufemiano Fuentes as a "one-man Wal-Mart of doping" in his 2012 book The Secret Race, which detailed the use of performance-enhancing drugs in the sport.
Hamilton was among 11 former teammates who testified against Lance Armstrong during the US Anti-Doping Agency's investigation.
In his only UK interview, he gave ITV News his reaction to Armstrong finally confessing.
More top news
Cancer battler Bradley Lowery is back in hospital with "horrendous pain" as doctors fear the disease is progressing.
Children's health services are being put at risk by a serious shortage of paediatricians and concerns over Brexit, a report warns.
A veteran has been accused of tying her therapy dog to a tree and shooting it dead while her soldier boyfriend filmed it.