Athletics chiefs have suspended 28 athletes after retesting of samples from the 2005 and 2007 World Championships revealed they may have taken banned substances.
Governing body the IAAF, which has been accused of a lack of rigour in anti-doping, said that the athletes could not be named yet for legal reasons but that most of them were already retired.
None of the athletes will compete at this year’s imminent World Championships in Beijing, which start on 22 August, and none are believed to be British.
The IAAF used new technology to trace previously undetectable substances and also took advantage of wider powers to punish cheats from up to 10 years ago.
“The IAAF embarked on this long-term storage and retesting strategy in 2005 to ensure that clean athletes are ultimately rewarded for their honest efforts in IAAF competitions,” it added.
The announcement comes after claims that the IAAF failed to act on thousands of suspicious blood test results over more than a decade.
The Sunday Times and German broadcaster ARD/WDR alleged that the findings indicated that as many as a third of Olympic and World Championship medallists between 2001 and 2012 may have doped.
The IAAF denounced the allegations as “sensationalist and confusing”, while its vice-president Lord Coe hit back at the claims, calling them “a declaration of war”.
Coe’s rival in next week’s presidential elections, former pole vaulter Sergei Bubka, called on the sport to be “more proactive and even more transparent” in efforts to tackle cheating.
London Marathon organisers this week added to criticism of the IAAF, saying they were alarmed at reports that seven winners of the men’s and women’s races between 2001 and 2012 may have doped.
Race organisers are pursuing 2010 winner Liliya Shobukhova for the return of £500,000 in prize money after the Russian had all her post-2009 results annulled for doping.