The international track and field association has appealed the Turkish Athletics Federation's decision to clear Olympic 1,500-metre champion Asli Cakir Alptekin of doping, and has re-imposed her ban.
The TAF cleared Alptekin in December, saying it found no violations of doping rules by the 28-year-old, who won gold at the 2012 London Olympics.
IAAF spokesman Nick Davies said the IAAF has lodged an appeal before the Court of Arbitration for Sport, meaning that she is ineligible to compete at home or abroad until the court has ruled.
Alptekin was provisionally suspended by the TAF last May after abnormalities were detected in her biological passport and she missed the world championships in Moscow in August.
The passport system tracks variations in an athlete's blood profile over time for signs of cheating.
The probe was prompted by an IAAF request last year that Turkey should investigate Alptekin.
Alptekin faces a lifetime ban for a second offence having served a two-year suspension in 2004 for a positive dope test at the world junior championships.
Doping scandals in Turkey last year may have hurt Istanbul's bid to host the 2020 Olympics, won by Tokyo. During the bid, Turkey maintained that the spate of doping cases were proof that the country was working hard to reduce cheating in sports.
