Russian officials have for the first time admitted the existence of a far- reaching doping operation which took place over several years.
In interviews with the New York Times, officials did not dispute accounts of the programme which has rocked the Olympic movement, although they denied the scheme was state-sponsored.
"It was an institutional conspiracy," Anna Antseliovich, the acting director general of Russia's national anti-doping agency, said.
Leading an investigation for the World Anti-Doping Agency, Canadian law professor Richard McLaren has found evidence that over 1000 Russian athletes in more than 30 Olympic and Paralympic sports were involved in a plot which began at least as early as 2011 and ran until 2015.