As many as 99% of Russian athletes are guilty of doping, a German TV documentary has alleged.
The programme claims that Russian officials systematically accepted payment from athletes to supply banned substances and cover up tests.
The documentary, shown by Das Erste, also implicates the International Association of Athletics Federations (IAAF) in covering up the abuse.
The Russian Athletics Federation (RAF) says the allegations are "lies".
However, both the IAAF and the World Anti-Doping Agency (Wada) have said they will look into the claims.
The IAAF said it had "noted a number of grave allegations" and revealed that an investigation into some of the claims was "already ongoing".