The Court of Arbitration for Sport (CAS) in Lausanne heard closing arguments in the Michelle de Bruin case yesterday and after the proceedings ended the three lawyers presiding over the case departed to their respective homes in Canada, Switzerland and England. They have until the last day of this month to reach a decision and gave no indication of when precisely they would do so.

Michelle de Bruin, who was not in court for the morning session, attended for closing arguments. Her husband and coach Erik has not been at the hearings.

Neither FINA nor representatives of the de Bruin camp would make comment on how they thought the case had gone. Peter Lennon, de Bruin's solicitor, suggested that he or his client might make a statement in response to a verdict but not before then.

Earlier the court heard closing arguments, first from Lennon and then Jean-Pierre Morand, acting for FINA.

Lennon suggested that the court could not feel comfortable allowing the ban on de Bruin to stand given the number of discrepancies of procedure he had highlighted. He said the testers, Al and Kay Guy, were incompetent and untrained, they had failed to challenge de Bruin on the whiskey odour, and he submitted that it was possible that the Guys had concocted the whole thing. There had been an unaccounted for omission on the athlete's portion of the doping control form (the time the test finished at) and this, he suggested, further highlighted the incompetence of the testers.

He added that the chain of custody arrangements for the sample were unsatisfactory, that the sample should not have been kept over the weekend in a fridge in the Guys house, and that the mission summary submitted by the Guys may have been made up later than they testified.

Lennon suggested that it was almost impossible for the laboratory in Barcelona not to have known that they were testing the sample of de Bruin. Asked if he was alleging that, perhaps, Dr Jordi Segura had manipulated the sample, Lennon replied that all possibilities had to be considered.

Asked by Yves Fortier where precisely all the theories and alternative possibilities were leading, Lennon replied "to the fact that there is a reasonable possibility that someone else manipulated the sample".

He added that he did not believe that Versapak's unique numbering system for doping kits was fail-safe. "Did someone else have a kit with the same numbers and infiltrate a DHL (the couriers) station or the home of Mr and Mrs Guy?" he asked.

Lennon said that he felt that his cross-examination of Dr Segura had acted as a rebuttal of the presumption of reliability of the IOC-accredited laboratory. His client had not been treated equally and he could draw no other conclusion that FINA had been looking "to get" de Bruin.

He asked that the panel consider both the possibility that somebody else had manipulated the sample and that, perhaps, it wasn't de Bruin's sample at all.

He said that at the time of the test his client had not been intending to compete as she was recovering from a car accident the previous autumn. Yves Fortier of CAS asked if evidence of this had been included in written testimony and Lennon conceded that it had not.

FINA, concluded Lennon, failed to discharge the burden of proof in the case and did not meet the standard of proof required in a case of this importance. He asked the court in the event of an acquittal to make an award for damages, taking into account the impact the hearing had had on his client's commercial viability.

"As you asked for it to be public, perhaps she could sue you jointly or separately," joked Yves Fortier.

Jean-Pierre Morand for FINA began with a parable suggesting that if a person goes into a department store and on the way out is caught by security with something in their pockets they have not paid for, it is not adequate to suggest that there is a possibility that somebody else put it in the pocket, or that by standing to close to a shelf the item may have fallen into a pocket.

He said that the appellant had failed to bring any concrete evidence other than to question the integrity of officials.

There had to be evidence of motive. To manipulate, a person had to have something to hide.

The sample of de Bruin had been found to contain a testosterone precursor. Segura, he said, had testified that this was ingested 10 hours before the test. Monard said that it was impossible for the court to ignore this, even if it were to rely solely on the evidence of the appellant herself.

He conceded that Al and Kay Guy had admitted to small mistakes and remarked that this honesty was a mark of their reliability, not otherwise. He suggested that the time-frame for the taking of the urine actually began from the moment Mr Guy arrived at the kitchen door and stood outside and, taken this way, it corroborated the Guys' claims as to how long de Bruin was absent.

"If the theory is that the Guys did it, why would they lie on irrelevant elements like the time the test finished? There is no logic there, it weakens their case if they lie. Even if they were over zealous and wanted to "get' the swimmer, they would have sent the sample immediately. And why add whiskey and risk invalidating the test?"

He said that the Versapak kits were used successfully in thousands of tests, rumours of breach without detection were only hearsay and the only evidence available, that of forensic expert Monica Bonfanti, suggested strongly that no tampering had occurred. He concluded by summing up the circumstantial evidence. The Guys smelt whiskey in the house. The dipstick gravity test, taken in Kellsgrange House by Al Guy and taken on the B sample in Lennon's presence on May 21st, had produced precisely the same reading, suggesting that the substance was that which had been on the table in Kilkenny. There was he said a strong motive for the appellant to manipulate the sample and "not a shred of evidence that anybody else might wish to do so".

De Bruin's case amounted to a shoplifter claiming "I'm sorry I don't know who put it in my pocket".

Winding up the oral part of the proceedings and taking the case under advisement, Fortier said that it had been a difficult case, testimony had aided the panel greatly, and that the ball was now firmly in the CAS court.

And there, with verdict pending, concluded the penultimate page in a key chapter of the story that has been central to Irish sport for more than three years now.