Twenty-eight athletes have been provisionally suspended by the International Association of Athletics Federations (IAAF) after retesting of samples collected at the 2005 and 2007 World Championships returned 32 adverse findings, it was confirmed on 11 August.
The names of those involved are yet to be released due to legal reasons, with the governing body further revealing that some of the number have already been sanctioned and '"very few" are still competing in the sport. None had been scheduled to travel to China for the 2015 World Championships, which are due to take place at the Beijing National Stadium between 22-30 August.
"The IAAF's long-term storage and retesting strategy concerning IAAF Championships which began in 2005 with the storage of anti-doping samples from that year's IAAF World Championships in Helsinki has led to disciplinary action being commenced against a further 28 athletes following a second reanalysis," the IAAF said in a statement released via its website.
"In 2012, the IAAF conducted a first round of re-analysis of urine samples taken at the Helsinki World Championships which had been proactively stored by the IAAF at the Swiss Laboratory for Doping Analyses (LAD), the WADA-accredited laboratory in Lausanne, in anticipation of new scientific developments. This strategy first revealed six adverse findings from Helsinki, which were announced in March 2013 and to date, nine athletes have been sanctioned following re-testing of samples from various world championships.
"Beginning in April 2015, using the latest technology available in the field of anti-doping and taking advantage of the new World Anti-Doping Code's provision extending from eight to 10 years the period during which samples can be tested, the IAAF made a second reanalysis of Helsinki 2005 and Osaka 2007 samples. This reanalysis has confirmed a further 28 athletes with 32 adverse findings."
The IAAF also revealed that such a re-analysis began before recent revelations from The Sunday Times in conjunction with German broadcaster ARD, which claimed more than 800 athletes recorded suspicious blood tests between 2001 and 2012. Meanwhile, 12,000 tests from 5,000 athletes were obtained as part of that investigation that was said to have uncovered "an extraordinary extent of cheating by athletes at the world's most prestigious events".
While the identities of those suspended are likely to remain undisclosed for the foreseeable future, the list of 28 is not believed to include any British athletes.
BBC sports editor Dan Roan tweeted: "I understand there are no Brits among the 28 athletes suspended by the IAAF today after re-testing of 05/07 samples."