The All-Russian Athletics Federation (ARAF) last month handed out two-year bans to seven Russian women athletes after they were ruled to have switched urine samples before tests to hide the fact they were using performance-enhancing drugs.

But the suspensions were backdated to last year meaning that the athletes are eligible to compete in the 2009 World Championships in Berlin.

The IAAF are now seeking to have the length of the suspensions extended.

Lamine Diack, the President of the IAAF, said: "It is unacceptable to the IAAF that these athletes who have committed serious and deliberate breaches of our anti-doping Rules would receive an effective ban of approximately 9-10 months and see them eligible to compete again in the summer of 2009."

The athletes were temporary suspended in late July by the IAAF "for a fraudulent substitution of urine which is both a prohibited method and also a form of tampering with the doping control process."

The ARAF carried out its own independent investigation in early September and completed it in October, passing a two-year ban for each athlete.

Diack said: "I consider the circumstances surrounding these cases warrants the IAAF to seek an extended ban over and above the minimum two year period."

Besides Tomashova, the athletes who were suspended include world indoor 1500m record holder Yelena Soboleva, hammer thrower Gulfiya Khanafeyeva, discus thrower Darya Pishchalnikova, and middle-distance runners Svetlana Cherkasova, Yulia Fomenko and Olga Yegorova.

Soboleva, Tomashova and Pishchalnikova were tipped to win medals for Russia at the Beijing Olympics.

All the athletes denied the allegations, but accepted the IAAF provisional suspension imposed just eight days prior to the start of the Beijing Olympics, they claimed, to avoid embroiling the Russian team in a scandal that could have affected their performance.

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