Mark Adams, Spokesman for the IOCs President, said this at a conference in Lausanne, Switzerland.
According to him, the Committee will be thoroughly checking athletes from the countries where the doping control systems do not match the international requirements.
This first of all concerns Russia, Kenya and Mexico.
Read also: U.S. opens criminal probe into doping by Russian athletes
In late May, it turned out that 14 Russian athletes had the banned substances in their blood samples during the 2012 Summer Olympics in London, when they had their blood checked by the IOC experts. The names of the athletes are so far kept in secret.
Two more Olympic champions from Russia Sergei Kirdyapkin and Olga Kaninskaya had to give away their medals they won at the 2012 Olympics - for the same reason.