(CNN) -- A total of nine athletes, including Olympic bronze medalist Nataliya Tobias, have tested positive for "sophisticated doping" offenses, the International Association of Athletics Federations (IAAF) has confirmed.
Six of those athletes were caught using a new "biological passport" method, which builds up a profile of each individual over a prolonged period of time.
The remaining three, including Tobias who came third in the women's 1500 meters in Beijing four years ago, were suspended after further analysis of samples they gave at the World Championships in Daegu last year.
"Today's announcements underline the IAAF's continued and unwavering campaign against doping in athletics," IAAF President Lamine Diack said in a statement on their official website.
"They demonstrate the IAAF's commitment to use advanced methods to detect doping and to enforce increased sanctions when justified.
"We will not stint in our resolve to do everything in our power to eradicate cheating."
The IAAF said they had been collecting samples from various athletes in the build up to the Olympics and would conduct 200 more biological passports during the Games.
That method accounted for six bans, for Morocco's Abderrahim Goumri, Greece's Irini Kokkinariou, Turkey's Meryem Erdogan, and three Russians -- Svetlana Klyuka, Nailiya Yulamanova and Yevgenina Zinurova, the 2011 European Indoors 800m champion.
Along with Tobias, fellow Ukrainian Antonina Yefremova was charged after synthetic testosterone was found in their systems, while Bulgaria's Inna Eftimova tested positive for a synthetic growth hormone.
All three athletes admitted the offense and waived their right to a "B" sample, meaning their four-year bans were halved.
The six caught via the "biological passport" method were flagged as suspicious in 2009 and were found to have persistently used banned substances over a long period, the IAAF said.
Four of the six -- Erdogan, Klyuka, Yulamanova and Zinurova -- admitted their offense and waived their right to a "B" sample, meaning their original four-year bans were cut in half.
The IAAF said Goumri had recently received a four-year ban by the Moroccan Athletic Federation, but was permitted to appeal as the decision had not yet been ratified by the IAAF.
Kokkinariou has been banned for two years by the Greek Athletic Federation but the IAAF said they were appealing to the Court of Arbitration for Sport to have it doubled on the grounds of "aggravating circumstances."
It was not immediately clear whether any of the nine athletes were part of Olympic teams set to participate in London 2012.