Berlin, Aug. 10 (Xinhua): German athletes are likely to sign a contract pledging that they are drugs-free if they want to take part in the 2008 Beijing Olympics, a leading official said.

"We are suggesting striking an agreement with all of the participants in the Olympics which, in the event of a doping offence, would lead to tough punishments, exclusion from the team and also having to pay back the costs of sending them to the Games," Michael Vesper, the general secretary of the German Olympic committee (DOSB), said in Sport-Bild magazine.

German sport was rocked this year after star cyclist Erik Zabel admitted he took the endurance-boosting drug EPO in 1996.