02/10/2015 09:51 EST | Updated 04/12/2015 05:59 EDT

Russian anti-doping chief compares country's race-walking doping to Lance Armstrong case

MOSCOW - Russia's anti-doping chief says there is evidence of systematic doping among the country's Olympic champion race-walkers and compares the case to that of Lance Armstrong.

Five Russian walkers, including three Olympic champions, were banned for doping last month. Five world championship gold medals from 2009 and 2011 look set to be re-awarded.

Russian anti-doping agency head Nikita Kamaev says the walkers' biological data shows "the systematic nature of the offences" in terms of the "methods" and "approaches" used.

Kamaev said further bans could follow but that the case was complex, adding that "the Armstrong case took more than 2 1/2 years. Our case is no simpler."

Armstrong was banned for life in 2012 for doping offences and stripped of his seven Tour de France wins.