A total of 67 Russian athletes have lodged appeals against their bans from this summer's Rio Olympics.
Olympic rings Photo: PHOTOSPORT
The Russian Athletics Federation is barred from international competition because of allegations of state-sponsored doping and cover-ups.
Clean athletes must pass extra doping checks and meet strict criteria for the IAAF to allow them to take part at this summer's Games.
But some athletes have now appealed to the Court of Arbitration for Sport.
Confirming the appeal, Russia's sports minister Vitaly Mutko did not name the 67 athletes.
However, 2004 and 2008 Olympic pole vault champion Yelena Isinbayeva may be on the list because she had already announced plans to challenge the ruling.
The IAAF set out the "exceptional eligibility" criteria for athletes that includes having their clean doping record verified by credible agencies - ruling out their own authorities.
Because the vast majority of Russian athletes train at home, the IAAF has already suggested "very few" will be deemed eligible.
The ban has been described as "legally indefensible" by the president of the Russian Olympic Committee, Alexander Zhukov.
The IAAF insists any Russian athletes cleared to compete in Rio must do so on a "neutral" basis and not under the Russian flag, as International Olympic Committee president Thomas Bach had suggested.
-BBC
