Russian athletes have been targeted in anti-doping testing ahead of next month's Winter Olympics in Pyeongchang, the International Olympic Committee announced on Thursday.
Over 14,000 tests on more than 6,000 athletes from 61 countries have been carried out by the IOC's pre-Games anti-doping taskforce, it said. The figures related to the period from April to December 2017.
"With extra scrutiny on Russian athletes, November and December saw testing on double the number of athletes from Russia than any other country," the IOC said.
The upcoming Games, which begin in South Korea on February 9, are the first Winter Olympics since it was revealed Russia manipulated anti-doping tests at the Sochi Games four years ago.
As a result, the IOC banned Russia's Olympic Committee from Pyeongchang in December. Only Russian athletes with a clean history will be able to compete in Pyeongchang, under the Olympic flag and as an "Olympic Athlete from Russia".
The IOC said it was conducting "the most rigorous pre-testing programme in Olympic history", with targeted testing, focusing "on specific disciplines and nationalities that are at particular risk, as well as individual athletes and groups of athletes selected based on their ranking, and any suspicious change in performance or adverse testing history".