Tour de France president Patrice Clerc has backed the news of the first positive doping test at this year’s race, and said it proves the current system is effective.

Liquigas rider Manuel Beltran was taken away for questioning by police on Friday after confirmation that he had tested positive for the banned blood booster EPO (erythropoietin).

The start of Saturday’s eighth stage from Figeac to Toulouse witnessed chaotic scenes at the start line media village as fears of yet another major doping scandal began to grow.

Clerc did not rule out the possibility of further cases, but he has called for calm.

The Frenchman who runs the Tour’s parent company, ASO (Amaury Sports Organisation), is convinced, following a raft of new measures brought in to fight doping, that Beltran’s case is isolated. “There is one cheat less at the Tour de France, it doesn’t necessarily mean there are others,” he said Friday.

“The AFLD (French national anti-doping agency) has done a remarkable job. I’m happy the controls are working, although I can’t say I’m happy. I’m stunned that some people still believe they can cheat and get away with it. “The only positive thing is that there is one less cheat on the race.”

He added: “The history of cycling, and past problems on the Tour de France mean that things tend to get blown out of proportion. “We have tightened the controls, the AFLD is doing a remarkable job – the proof being that we have caught a cheat, as they do regularly in other sports without it being totally blown out of proportion.”

The news of Beltran’s positive test came just over a week after tests on a blood sample, taken by the AFLD from the 180-strong peloton, alerted controllers to abnormalities.

A further test was carried out on a urine sample, taken from the race’s first stage, and it detected the EPO. Beltran, best known for helping Lance Armstrong to the last three of his seven Tour de France wins, has been suspended by Liquigas while he awaits the results of a B sample test.

If that proves positive, he will be sacked and could be taken to court by the lime green-clad Italian outfit for damages.

The team were allowed to start the eighth stage without Beltran because, in accordance with the contract signed by all race teams and organisers, teams can only be forced out of the race if it is believed they have helped a rider to dope.

Team manager Robert Amadio said on Friday: “We have an active anti-doping programme in place, so for us if this result is confirmed it is an isolated case.”

Reports suggested on Friday that test results from between 10 and 20 riders had alerted the AFLD to suspect blood parameters.

A report in L’Equipe newspaper on Friday, for example, revealed that Italian Riccardo Ricco has a naturally elevated haematocrit (volume of red blood cells in the blood) level.

Boosting of blood, either by transfusion or the use of drugs like EPO, is one of the principal methods of enhancing performance – hence the introduction of a ‘legal’ threshold of 50 percent haematocrit reading in cycling by the International Cycling Union (UCI).

However Clerc said that a “certain hysteria” had been created around the fact that some riders’ test results revealed parameters that could be construed as “abnormal”, but which showed no proof of doping.

“Everyone in this business knows that not all riders have the same haematocrit levels,” he added. “I think it’s irresponsible to start throwing names and figures around like that. All it does is create hysteria and turns it into a hunt for suspects.”