Spanish rider Iban Mayo had been targeted by the International Cycling Union (UCI) as a possible offender prior to his positive test for erythropoietin during the Tour de France.
Mayo, who finished the race in 16th place, was suspended by his team Saunier Duval on Monday after cycling's governing body confirmed traces of EPO in a sample taken on the July 24 rest day.
"It's another sad episode in the Tour de France," UCI president Pat McQuaid told Reuters by telephone yesterday.
"People need to understand, the riders need to understand that the UCI operates in a different way than in the past. Thanks to the blood tests, we target riders.
"Iban Mayo was one of the UCI targets," he added. "The riders have to understand that we use intelligence to target some of them."
EPO is a blood-boosting substance that was at the centre of the Festina affair that tarnished the 1998 Tour.
"It is surprising that the riders still use it knowing it is detectable," McQuaid said.
Lab collaboration
The UCI chief added that Alexander Vinokourov, who tested positive for homologous blood-doping, was probably unaware that the French laboratory used by Tour organisers had mastered detection methods for this kind of offence.
"Up to this year, only the Lausanne laboratory was conducting tests for homologous blood-doping," McQuaid said. "But the Lausanne lab taught the French one how to detect it and therefore they were able to test Vinokourov's sample."
The Kazakh rider tested positive following his stage 13 time-trial victory in Albi and was forced to leave the race, prompting his Astana team to pull out of the Tour.
In a race marred by a series of doping affairs, Italian rider Cristian Moreni tested positive for the male sex hormone testosterone and was kicked out of the race.
His Cofidis team abandoned the Tour almost immediately. Dane Michael Rasmussen, who was race leader at the time, was sacked by his Rabobank team before the 17th stage for lying about his training whereabouts.
Meanwhile, French Sports Minister Roselyne Bachelot called for tougher sanctions against doping.
"Sanctions must be increased," Bachelot told a news conference in Paris.
"I will propose a series of tougher measures. For example, doping is banned but keeping banned products or transporting them is not."
"If there's no traffic, there's no doping," she added.