By Nigel Wynn
Tyler Hamilton has announced his immediate retirement from professional cycling after failing an out-of-competition drugs test in February.
The American Rock Racing rider failed a test for banned steroid found in a readily available anti-depressant. Hamilton has admitted that he knew he was taking a banned substance and has decided to permanently withdraw from the world of cycling.
Hamilton sensationally failed a test for homologous blood transfusion at the 2004 Vuelta a Espana - in the same year that he won the Olympic Games time trial. He subsequently served a two-year ban from competition but retained his Olympic title.
Hamilton always protested his innocence after the 2004 failed test, but is not putting up any fight in this latest case for which he would likely face a lifetime ban.
Hamilton's name has also been linked to the Operacion Puerto investigation centred around the Madrid clinic of Dr Eufemiano Fuentes where police found evidence of organised blood doping.
Internet rumours have been circulating since February that Hamilton failed a test at the Tour of California. At the time, sources at his Rock Racing team declined to confirm or deny the rumours.
This latest doping scandal is not good news for American cycling, Hamilton is the current US professional road race champion.
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