Seven athletes failed drugs tests at August's World Championships, the International Association of Athletics Federations has announced.
Roman Avramenko of Ukraine, who finished fifth in the men's javelin, was the only one of the group to reach a final at the event in Moscow.
The IAAF said that all seven have been sanctioned or provisionally suspended.
Positive tests at Moscow 2013
- Roman Avramenko, (Ukraine, javelin)
- Massoud Azizi (Afghanistan, men's 100m)
- Elyzaveta Bryzgina (Ukraine, women's 200m)
- Ayman Kozhakhmetova (Kazakhstan, women's 20km walk)
- Ebrahim Rahimian (Iran, men's 20km walk)
- Yelena Ryabova (Turkmenistan, 200m)
- Jeremías Saloj (Guatemala, men's marathon).
It had promised a stringent testing programme in Moscow after a recent series of high-profile doping cases.
Former world champion Tyson Gay and ex-100m world record holder Asafa Powell
both tested positive for banned substances
ahead of the championships.
Their doping positives were made public in July, a month after it was announced that Veronica Campbell-Brown, 200m champion at London 2012,
had tested positive for a banned diuretic
- something which is viewed as a masking agent by the World Anti-Doping Agency.
The 25-year-old Avramenko recorded a personal best throw of 84.48 in June before competing in Moscow, Vítezslav Vesely of the Czech Republic won the gold medal.
Avramenko tested positive for the steroid dehydrochloromethyltestosterone.
The other athletes found to have tested positive at the World Championships were Massoud Azizi (Afghanistan, men's 100m), Elyzaveta Bryzgina (Ukraine, women's 200m), Ayman Kozhakhmetova (Kazakhstan, women's 20km walk), Ebrahim Rahimian (Iran, men's 20km walk), Yelena Ryabova (Turkmenistan, women's 200m) and Jeremías Saloj (Guatemala, men's marathon).
The IAAF said that in addition to taking urine tests from 538 athletes in Moscow, 1,919 blood samples were collected as part of its Athlete Biological Passport programme, designed to detect abnormalities in an athlete over time.
The president of the IAAF, Lamine Diack, said: "The specialised analyses and the blood samples taken in connection with the Athlete Biological Passport emphasise the IAAF's firm commitment and resolve to use the most sophisticated methods at our disposal in the fight against cheating in sport."