"Unfortunately, we can't go back 20, 30 or 40 years. All we can do now is join fully the current battle against doping, and that is what we are doing, to help doping disappear from sport."

Some athletes were kept in the dark over the programme in Czechoslovakia, while the documents show others were not only aware but sought extra doses of banned substances.

Those who refused to join the programme often found themselves kicked out of their sport.

One handwritten letter shows a weightlifter asking for help from the Communist authorities because his failing health was keeping him from earning enough money.

In the letter he says a local doctor of internal medicine who examined him noted chronic liver and other problems were the result of taking anabolic steroids.

Bugar, who won the discus competition at the world championships in Helsinki in 1983 and an Olympic silver medal in 1980 in Moscow, was shocked to find his name on several of the documents obtained.

"I don't understand it. To this day, I believe I was as clean as God's word," Mlada Fronta Dnes quoted the 51-year-old Bugar as saying when shown the documents.