The International Athletics Federation (IAAF) on Friday announced that a re-testing of samples from the 2005 World Championships in Helsinki has revealed six new cases of doping.
"The six adverse findings involving Andrei Mikhnevich, Ivan Tsikhan, Vadim Devyatovskiy, Tatyana Kotova, Nazdeya Ostapchuk and Olga Kuzenkova have resulted in the initiation of disciplinary procedures which are currently ongoing in accordance with IAAF Rules," read a statement published on the IAAF's website.
IAAF President Lamine Diack added: "The IAAF's message to cheaters is increasingly clear that, with constant advancements being made in doping detection, there is no place to hide.
"This re-testing is just the latest example of the IAAF's firm resolve to expose cheating in our sport.
"The IAAF will continue to do everything in its power to ensure the credibility of competition, and where the rules have been broken, will systematically uncover the cheats.
The IAAF had already announced last month the provisional suspension of Russian long jumper Kotova following re-analysis of a sample taken in Helsinki, where she won one of her three World Championship silver medals.
Her fellow Russian, hammer thrower Kuzenkova, was the Olympic champion in 2004 and world champion in Helsinki, but retired in 2007.
Tsikhan, of Belarus, another hammer thrower, has won three world titles, including in Helsinki.
However, he was not allowed to attend last summer's London Olympics having already shown up positive in a re-analysis of samples from the 2004 Athens Games.
He also tested positive for testosterone at the 2008 Beijing Games, as did his compatriot Devyatovskiy, who came second in Helsinki in 2005.
The duo, who won bronze and silver respectively in Beijing, were stripped of their medals by the International Olympic Committee before having them reawarded after appealing to the Court of Arbitration for Sport.
Mikhnevich, another Belarusian, won the world shot putt title in 2003, while compatriot Ostapchuk was involved in controversy at the London Games.
She won shot putt gold, but was later disqualified after two samples revealed the presence in her blood of the anabolic agent metenolone.
New Zealand's Valerie Adams was awarded the gold in her place.