BBC Sports News Correspondent Gordon Farquhar: "The end of de Bruin's career"

But she continued to plead her innocence as she left the sport and insisted she was proud of what she had achieved.

Fina, the sport's governing body, suspended the Irish swimmer last August, ruling that she had tampered with a urine sample.

The sample, which was taken from her in January 1998, was found to contain lethal levels of alcohol.

De Bruin, who shot to fame under her maiden name Smith at the 1996 Olympics in Atlanta, immediately objected to the test.

A Court of Arbitration for Sport in Lausanne heard the appeal last month - and on Monday it decided that de Bruin "was the only person who had the motive and opportunity to manipulate the sample".

Saddened

In a statement de Bruin said: "I am deeply saddened by the decision of the Court of Arbitration for Sport and in particular their decision to prefer circumstantial evidence concerning the (drugs testing) manipulation charge, as distinct from direct evidence given by me at the hearing of my appeal."

De Bruin had two strands to her appeal - she tried to convince the panel that the sample was not hers and also that a third party may have manipulated them in order to adulterate their content.

She added: "I stand accused of having used banned substances over the course of my career.

"I reaffirm that I have never used any banned substance in the course of my career, nor have I ever been charged by FINA of using any banned substance in the course of my career.

"I am proud of what I have achieved and assure those who have supported me and believe in me that my victories in Atlanta were not hollow and were achieved without the use of any illegal performance-enhancing substance."

Disgraced

The shamed swimmer sparked rumours of drug-taking at Atlanta, when she came from obscurity to beat a host of more illustrious competitors and went home with three golds and a bronze medal.

However, she always dismissed the claims as part of a whispering campaign begun by her rivals in the pool.

This ruling means de Bruin will be unable to defend her Olympic gold medals in the 200m and 400m medley and 400m freestyle in Sydney next year.

It also makes her ineligible for the 2001 world championships in Fukuoka, Japan.

De Bruin will be aged 32 before she can compete again.

She is married to former Dutch discus champion Erik de Bruin, who is also her coach and manager and who had previously been banned for taking performance-enhancing drugs.

Diminished glories

The Republic of Ireland's former minister for sport, Bernard Allen, bemoaned "a black day for Irish sport" after the verdict.

Allen was in office when de Bruin shocked the swimming world at Atlanta and led official celebrations of her record-breaking performances.

He said the news de Bruin had lost her appeal was "a tragedy for herself, her husband and her family."

Now the Fine Gael Irish parliamentary opposition party's sports spokesman, Allen added it "has seriously diminished the glories of Atlanta".