PARIS: Lawyers working to prove that Alberto Contador doped at the 2010 Tour de France came “very close” to walking out in protest at his hearing before the Court of Arbitration for Sport, which will soon rule on his fate, upset over the silencing of testimony and the conduct of judges, including one with connections to Contador’s home country of Spain, the Associated Press has learned.

The revelations from people directly involved in the complex and lengthy case come as the court, sport’s highest legal body, prepares to rule whether the three-time Tour winner should be banned for testing positive for the performance-enhancer clenbuterol or whether Spanish authorities were right to clear him.

Contador says the clenbuterol came from beef he ate while on the Tour. Lawyers for the World Anti-Doping Agency and the International Cycling Union, the sport’s governing body, presented the CAS panel with another scenario for the failed test: Clenbuterol entered his body via a banned, performance-boosting blood transfusion.

The three CAS judges, however, stunned WADA lawyers by blocking oral testimony from one of their witnesses, Australian doping expert Michael Ashenden, hearing participants told the AP. They spoke on condition of anonymity, concerned that disclosing events from the closed-door proceedings in November could annoy the arbitrators and perhaps sway their deliberations.

Hearing participants said Ashenden, if allowed, could have expanded on the theory that Contador may have had a blood transfusion on July 20, followed the next day by an injection of blood plasma.

The Tour was in its third week at that point, and Contador was nursing a lead of just 8 seconds over his Team Saxo Bank rival Andy Schleck, following three punishing days of mountain climbs in the Pyrenees.

A transfusion would have supercharged Contador for the final four stages to the finish in Paris, especially on the last day in the Pyrenees on July 22, when he stuck a glue-like substance to Schleck’s wheel up the fabled Col du Tourmalet, and during the time trial in Haut Medoc wine country on July 24, when Contador widened the gap over Schleck to 39 seconds – a lead he carried to the Champs-Elysees finishing line the next day.

Contador has steadfastly denied having a transfusion. “It is a science fiction story,” his spokesman, Jacinto Vidarte, told the AP in October 2010.

If CAS rules against him, Contador can expect a two-year ban and could become only the second Tour champion to be stripped of a victory for doping. The first was Floyd Landis, the 2006 winner.

There is no conventional doping test to spot when athletes transfuse their blood. Further confusing this case is that urine samples Contador gave on July 20 and on July 21 produced different results.

The July 20 sample had no clenbuterol, but did contain traces of plastic residues that could have come from plastic pouches often used to store blood, hearing participants told the AP.

The July 21 sample did contain a very low concentration of clenbuterol, but no plastic traces.

Ashenden could have explained to the CAS that Contador might have had a blood transfusion on July 20 which was uncontaminated by clenbuterol but which perhaps was stored in a plastic pouch, followed the next day by an injection of blood plasma.

Under this theory, the plasma could have been contaminated with clenbuterol, but may have been stored in a different sort of bag – a type that didn’t shed telltale traces of DEHP, a plasticizer used in medical devices such as intravenous tubing and blood bags.

Lawyers for Contador, however, objected on procedural grounds to Ashenden testifying about that part of WADA’s argument, specifically about why DEHP residues showed up in the first sample but not the second, hearing participants told the AP.

Contador’s lawyers argued that if he transfused, clenbuterol and plastic residues would have appeared together in his July 21 sample and because they didn’t, the transfusion scenario was impossible. His lawyers also called an expert on DEHP who testified that plastics in Contador’s July 20 sample could have come from drinking from a plastic bottle, through a plastic straw or from other sources which had nothing to do with doping, a participant said.

The CAS arbitrators ordered the chamber emptied while they deliberated and then called the parties back.

The chairman, Efraim Barak, announced that WADA lawyers were not allowed to question Ashenden about these transfusion issues but could cross-examine an anti-doping consultant for Contador’s side, Paul Scott.

Participants said WADA lawyers were so rattled by the judges’ handling of this dispute that they debated whether to walk out.

One said they came “very close to doing it.”