There is no good or bad time to fail a doping test. But the eve of the Olympic Games is the worst moment of all.

The whole world is watching and whoever tests positive can neither run nor hide.

That’s the reality now for Irish boxer Michael O’Reilly: he’s the storm in the calm before the opening ceremony. And for a sport expected to deliver Ireland’s best chances of a medal, the ripple of his doping offence was always going to become a major splash.

That the news broke on Thursday morning during the final weigh-in for the boxing competition merely highlighted the sense of worst possible timing (especially given there was no respect for due process).

It had come from nowhere: no rumour and, at least within Irish boxing, no precedent.

Yet there was also the sense that Irish sport has been here before. Our relatively new, though not brief, history of doping offences have almost all come before, during or after the Olympics, with varying degrees of lasting damage.

What unfolds over the next 48 hours will reveal a lot more about what exactly O’Reilly is guilty of, and the damage it might do to Irish boxing.

Main contender

It is almost certain his Olympics are over. For the 23-year-old from Portlaoise, who is one of the main contenders for a medal in his middleweight division, that’s a massive blow.

The timing of it all isn’t helped either by the fact it’s come on the back of some fresh recollections from our most damaging Olympic doping scandal of all, the 20th anniversary of the still disturbing ripples of suspicion that Michelle de Bruin caused in the swimming pool during the 1996 Olympics in Atlanta, winning more individual gold medals at those Atlanta Olympics than any other athlete from any nation, in any sport.

At a time when Ireland didn’t have even one Olympic-sized swimming pool, her three gold medals, plus one bronze, certainly had the world paying lots of attention.

Not many people believed in her then and less so in January of 1998, when a doping sample given by de Bruin was revealed to contain a level of alcohol that would have been fatal if consumed by a human. The sample led to her receiving four-year ban.

But if questions over de Bruin will always remain, there was no denying the damage done by Irish distance runner Cathal Lombard on the eve of the Athens Olympics in 2004: he was notified of his positive test for EPO during his final training camp in Italy.

Lombard immediately admitted using EPO, accepted his two-year ban and claimed he had done so merely to “level the playing field”, much to the disgust of many of his team-mates.

“More like, to get to the playing field,” fellow Cork athlete Mark Carroll responded.

In the aftermath of Athens, Ireland was also forced to hand back an Olympic medal for the first time in our history.

Two months after Cian O’Connor had rode Waterford Crystal to the individual show jumping gold, it emerged his horse had tested positive for the banned substances fluphenazine and zuclopenthixol, both leg sedatives.

The investigation by the International Equestrian Federation decided O’Connor had not deliberately attempted to influence the performance of the horse, although he had to return the gold medal.

Four years later, in Beijing, Denis Lynch was considered Ireland’s best chance of a medal, also in the individual show jumping, only for his horse, Lantinus, to be pulled on the morning of the final, again after a positive doping test.

It later emerged Lantinus had also tested positive for a substance known to be on the banned list, after which Pat Hickey, president of the Olympic Council of Ireland, threatened to ban the Irish equestrian team from participating in future Olympics.

Marathon

Almost four years after competing in the marathon in Beijing, Martin Fagan failed a doping test. He also admitted to using the banned blood-boosting drug EPO in his efforts to qualify for the London Olympics. He too accepted a two-year ban, but after briefly returning to the sport and qualifying for the Rio marathon, he retired permanently, claiming he didn’t feel entirely welcomed back.

What Fagan’s case suggested as well is that there is no such thing as a good or bad way to recover from a doping test.