The whistleblower at the centre of doping allegations against a London-based doctor has accused the UK anti-doping agency (Ukad) of a "catastrophic failure".
Speaking to BBC Sport, former amateur cyclist and drugs-cheat Dan Stevens said the organisation had "absolutely no reason to not investigate" his warnings over Dr Mark Bonar.
Bonar was caught on camera by The Sunday Times, allegedly claiming to have prescribed banned substances to 150 athletes, including Premier League footballers.
Three Premier League clubs subsequently issued statements denying their players had used performance-enhancing drugs.
Bonar also denies any wrongdoing.