Meanwhile, lawyer for Manolo Saiz says he won't now be calling Alberto Contador as a witness...

Tyler Hamilton has told the Operacion Puerto trial in Madrid how his urine turned black with blood after he began to feel unwell following a transfusion during the 2004 Tour de France. Meanwhile, it has been confirmed that Alberto Contador, due to give testimony later this week, will no longer be called as a witness.

Hamilton, who was speaking via video link, confirmed that from 2002 to 2004, he had paid €110,000 to Eufemiano Fuentes, the doctor who is standing trial with others on charges relating to public health.

Now aged 41, the American has previously related the incident in his book The Secret Race, co-written with Daniel Coyle and in which he goes into extensive details about his dealings with the doctor he knew as ‘Ufe.’ The transfusion in question wasn’t administered by Fuentes himself, but by staff of Hamilton’s team at the time, Phonak.

He told the court that he had met Fuentes around 15 times, including at the doctor’s clinic in Madrid and at a number of hotel rooms during the time he was a client, but discontinued their relationship when the blood of another rider was mistakenly transfused into his system.

Hamilton tested positive for an illegal blood transfusion during that year’s Vuelta, as would Phonak team mate Santiago Perez, said to be the other rider involved.

His samples from the time trial at the 2004 Olympic Games in Athens would also test positive, and last year he returned the gold medal he had won there to the International Olympic Committee.

Giving his testimony at the Spanish embassy in Washington, DC and speaking through an interpreter, Hamilton was reported by Reuters as saying: "I had a transfusion in July of 2004 that gave me a bad fever and I felt sick.

"The reason why I knew was that 30 or 40 minutes later when I went to the bathroom my urine was black.

Speaking of his working relationship with Fuentes, Hamilton said: “He gave me a calendar with a schedule of races, a schedule of when to take what performance-enhancing drug and if I remember right he gave me EPO.

"He offered me EPO, testosterone, growth hormone, insulin, I think that's it," adding that “my biggest fear was something like this [Operacion Puerto] would happen."

He claimed that he didn’t continue all the substances he says Fuentes provided. "The insulin I tried one time but did not like the way it made me feel, sweating, increased heart rate, just a strange sense.”

Regarding blood transfusions, he went on: "You'd always feel a little bit different. I would say that no two times were exactly the same. But yeah your body reacted to the blood extractions and re-infusions."

He also revealed that in 2002, he had a blood transfusion administered by former mountain biker Alberto Leon, who had no medical training but worked with Fuentes.

Leon committed suicide in January 2011, shortly after being implicated in another doping scandal surrounding Fuentes, called Operacion Galgo, which focused primarily on track and field athletes.

The trial, which is scheduled to continue for another four weeks, had been due to hear testimony from Alberto Contador on Friday, but he will not now be required to appear.

When the Operacion Puerto scandal broke in 2006, the Spaniard was riding for the Liberty Seguros team, which Fuentes worked with, and which was managed by Manolo Saiz, one of the co-defendants in the current trial.

Contador was investigated for alleged links to Operacion Puerto in 2006, but was formally exonerated of any involvement by the Spanish authorities.

Yesterday, Saiz’s lawyer Ignacio Arroyo confirmed he would no longer be calling Contador, stripped of the 2010 Tour de France title after testing positive for clenbuterol during that race, as a witness in the Operacion Puerto trial.

Born in Scotland, Simon moved to London aged seven and now lives in the Oxfordshire Cotswolds with his miniature schnauzer, Elodie. He fell in love with cycling one Saturday morning in 1994 while living in Italy when Milan-San Remo went past his front door. A daily cycle commuter in London back before riding to work started to boom, he's been news editor at road.cc since 2009. Handily for work, he speaks French and Italian. He doesn't get to ride his Colnago as often as he'd like, and freely admits he's much more adept at cooking than fettling with bikes.