In a quiet room near the lake in Lausanne today Michelle de Bruin reaches the end of a process which began with a knock on the door of her house in Kells, Co Kilkenny, 17 months ago.

When Al and Kay Guy came calling to Kellsgrange House they could scarcely have envisaged becoming embroiled in the bitter battle which climaxes in the Court of Arbitration for Sport (CAS) here this morning. Nor could they have imagined the sort of spectacle which the first public hearing the court has held will create.

All parties to the epic story which has been at the centre of Irish sport for more than three years now will be present today to hear what will, in all likelihood, be the final legal stage of the case. Although she has spoken about a possible recourse to the European Court of Human Rights, de Bruin is in fact bound by the arbitration process and it would take an extraordinary sequence of events for her to extricate herself from that and to have a case accepted elsewhere.

With the stakes so high it is likely that the hearings today and tomorrow will be extremely detailed affairs, with the audience in danger of suffocation beneath a welter of evidence relating to polymers, specific gravity and laboratory methods.

The hearing will be held by three lawyers: Yves Fortier (Canada), Denis Oswald (Switzerland) and Michael Beloff (England).

It was confirmed some time ago that part of Michelle de Bruin's appeal brief to the CAS will be to question the right of FINA, swimming's governing body, or their agents to conduct out of competition doping controls on the swimmer. This tactic was part of the defence case brought by de Bruin to the FINA hearing this summer at which the Irish swimmer received a four-year competitive ban.

As such, it represents a significant deviation from the swimmer's frequent declarations of support for FINA's drug testing programme.

The De Bruin team will also rely heavily on attacking the credibility of the couple who tested the swimmer last year, Al and Kay Guy. The grounds for appeal explicitly accuse them of bias and of tampering with the sample. In support of this evidence they are likely to use research from the Paul Edwards case in Britain which suggested that the Versapak doping control containers used can be boiled open and then resealed.

FINA will state that they satisfied the de Bruins' solicitor, Peter Lennon, by discounting all evidence supplied by the Guys at the original hearing last summer and relied solely on the account of events as given by Michelle de Bruin herself.

Versapak, who have a significant interest in the outcome of the case also, are expected to offer evidence based on research done by oil companies that they can, by examining the polymers in plastic, determine whether they have been subjected to boiling.

If de Bruin were to be cleared on either of the above points of law (the right to test or the adequacy of the equipment), the implications for the entire business of drug testing in sport are huge. A massive number of appeals and civil cases could be expected as the mechanism is thrown into chaos Mathieu Reeb, of the CAS, expects the hearings which start at 9.0 this morning will run through till 6.0 p.m. today and tomorrow.

The nature of the proceedings is evidentiary, with the lawyers arbitrating the case seeking expansion and clarification on case notes and evidence which they have been studying for some months following a procedure of appeal briefs being lodged and the parties both responding.

FINA sources have described the case lodged by the de Bruin team as "nothing new," while Lennon, who flew to Switzerland with Michelle de Bruin yesterday, will be emphasising that the FINA panel which judged the case last summer "erred in law" on a number of points.