Cyclists have rendered advances in drug testing meaningless with methods designed to evade controls, according to the French rider Philippe Gaumont.
Gaumont has detailed a litany of cheating methods in cycling
Gaumont has told the French newspaper Le Monde that he has taken drugs in all but one of his 10 years in the sport.
He said the blood-boosting drug EPO has been replaced by transfusions as a method of increasing endurance.
The former Cofidis rider went on to list a series of methods used to illegally boost cyclists' performance.
Gaumont is under investigation by police for possession of drugs in an inquiry into drug-taking in the Cofidis team.
"First off, there are products that they don't know how to
detect, like growth hormones, which cyclists can use as
they like," Gaumont was quoted as saying.
He added that blood transfusions had become popular to boost red blood cell counts - and therefore the blood's capacity to carry oxygen - because of a test introduced three years ago to detect EPO.
The test only works if the drug has been used within the previous three days, so EPO is used only when a cyclist knows he will not be tested.
"The tests occur during training and races," Gaumont is quoted as saying.
"Every rider knows that intravenous erythropoietin (EPO) stays for three days in the urine. So you just have to act consequently and stop the treatment three days before the test.
"And the effect of EPO is still effective 10 days after you
He added: "The haematocrit [blood thickness count] of a cyclist coming to the Tour [de France] can drop from 50% to 44 or 45 after a week.
"With one bag of blood a week, a cyclist can keep it at 50, while the other guys finish the tour at 40%.
"But only the big names can use this because you have to pay a doctor to do the transfusions."
Gaumont also said cyclists use false prescriptions to permit the use of banned cortico-steroids.
"The team doctor sends you to an allergy specialist, he diagnoses that you are sensitive to mites and prescribes a nasal spray," he said.
"We were told to ask for Nasacort, at all costs. Why? Because it means you can use cortisone. At the control they can't tell the difference between the spray and an injection.
"Then the doctor sends you to a dermatologist.
"You scratch your testicles with salt, show the doctor they're all red, and he prescribes you six months' worth of Diprosone cream. Then you can inject Diprostene [a banned liquid suspension] without risking being positive."