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Spanish cyclist Roberto Heras, a former lieutenant of Lance Armstrong and a three-time winner of his national tour, the Vuelta Espana, has become the fifth big-name doping-tarnished cyclist to retire.
In October, Heras finished a two-year ban after testing positive to the blood-booster EPO. A code of ethics recently implemented in the sport prohibits those banned for doping from signing with a ProTour team for a further two years.
The 33 year-old had previously raced for Liberty Seguros, Kelme and US Postal. He is one of several riders who recently retired either after positive doping tests or an inability to find a satisfactory contract.
Others include three time Tour de France podium finisher and Spaniard Joseba Beloki, Kazakh Alexander Vinokourov, former World Champion Laurent Brochard and Spain's Oscar Sevilla.
