Russia should be banned from athletics competition, a World Anti-Doping Agency commission report has recommended.
Wada's independent commission examined allegations of doping, cover-ups, and extortion in Russian athletics, which also implicated the IAAF, the sport's world governing body.
It says London 2012 was "sabotaged" by "widespread inaction" against athletes with suspicious doping profiles.
Russia was also accused of running a "state-supported" doping programme.
The report recommended that five athletes and five coaches should be given lifetime doping bans.
IAAF president Lord Coe told media that the Russian athletics federation, Araf, had been asked to respond to the allegations by the end of the week. The 59-year-old said that after reviewing the feedback the IAAF "would look at a range of options, including sanctions", which could result in suspension from the sport.
"I'm not putting in a time frame but I will do whatever is necessary. This is not a swift road back," he added.