Alexander Vinokourov, suspended for blood doping by his national federation, announced his retirement from the sport at a press conference in Almaty, Kazakhstan, on Friday.

The 34-year-old and his Astana team were kicked out of the 2007 Tour de France after he tested positive for homologous blood doping.

"I am stopping competition ... It's a definitive decision," he told a news conference. "I don't want this sport anymore ... I'm slamming the door and I'm leaving."

Vinokourov was fired by his Kazakh-financed, Swiss-registered team following the positive test, which indicated the presence of a secondary population of red blood cells, evidence that he had injected blood from a donor in order to enhance his endurance. Following the result, the entire team pulled out of the Tour.

The following month, teammate Andrey Kashechkin was found positive for the same infraction. Kashechkin, too, has denied guilt and has filed a law suit, challenging the UCI's authority to demand blood and urine samples from riders.

Despite his decision to retire, Vinokourov said he is considering an appeal of Thursday’s ruling by the Kazakh Cycling Federation to suspend him for a year.

"It's sad that my career is ending like this but I want to restore my honor ... I will prove that I'm not guilty and get the results of this test rescinded," he said.

The Kazakh cycling federation banned Vinokourov for one year, a decision that would have allowed him to compete at the Beijing Olympics as his suspension runs up to July 2008, the month before the games start.

But officials from the UCI, cycling's international governing body, expressed concern over the light penalty as cycling rules – in keeping with the World Anti-Doping Code – call for a two-year suspension for a first offense and a life-time ban for subsequent violations.

Vinokourov, who said that he would be consulting his American attorney, Maurice Suh, regarding an appeal of his suspension, blamed anti-Kazakh bias for his problems.

"When we built the Astana team people started to talk behind our backs asking where are these Kazakhs coming from?” he said. “They told us they didn't want us in Europe.”

Vinokourov, long considered a Tour de France contender and winner of the 2006 Vuelta a España, claimed that doping was not more rife in cycling than in other, more high-profile, sports which were protected from scandals by their financial clout.

"I don't think cycling is dirtier than any other sport,” he said. “We're 150 people, where are the others? Where is tennis, where is football? They've been told not to touch them.

"I've the impression that cycling is an orchestra with very good musicians but a bad conductor. That's the reason the sport is a mess."