Berlin - Five-time Olympic speed skating champion Claudia Pechstein is to use what she believes are several procedural errors by the ruling body ISU in an attempt to overturn a two-year ban handed down for doping.

The 37-year-old German has protested her innocence and told a press conference Thursday in Berlin that eight of the 20 blood test results used by the ISU were not identical with that of the athlete.

Pechstein was recently banned for two years by the ISU for abnormally high levels of reticulocytes (immature red blood cells) on several occasions, including the allround world championships in February in Norway.

Pechstein, who never submitted a positive test, has submitted an appeal before the Court of Arbitration for Sport (CAS).

Pechstein, the most decorated German Winter Olympian with five gold, two silver and two bronze medals, is the first athlete to be banned over screenings in the biological passport, which is also other sports such as cycling and various ski sports.

The issues will likely be at the centre of the CAS hearing set to take place in autumn. (dpa)