Camenzind quits cycling

Camenzind has been fired by Phonak

Cyclist Oscar Camenzind has retired from the sport after failing a drugs test in the build-up to the Olympics.

The 1998 world champion tested positive on 22 July for the banned endurance drug erythropoietin (EPO).

Under Swiss cycling federation rules, a rider is automatically suspended if a first test shows up positive.

The positive test saw him excluded from Switzerland's Olympic team, his country have yet to name a replacement - and he was also fired from his Phonak team.

Zurich-based Phonak said in a statement that Camenzind accepted full responsibility for the incident.

"Every rider who, during racing or training, is tested positive for a performance-enhancing substance, or carries such a substance with him, must count on being dismissed immediately," said Phonak team manager Urs Freuler.