Four previous Irish doping scandals that rocked the country
There have been a relatively small number of Irish athletes banned for alleged doping but the cases have all received widespread coverage.
Michelle de Bruin
The swimmer had a nightmare fall from grace just two years after winning three gold medals and a bronze at the Olympics in Atlanta in 1996.
Michelle has always denied taking performance-enhancing drugs. As her father Brian pointed out recently, she was tested eight times during the Games, but the results were always negative.
But Michelle's goose was cooked in 1998 when two testers arrived at her home in Kilkenny and she was asked to give a urine sample.
When the sample arrived in the lab in Barcelona, it was found that it gave off "a very strong whiskey odour''. She was found guilty of interfering with the sample.
Riding his horse, Waterford Crystal, showjumper Cian O'Connor became an instant national hero when he became the only Irish medalist at the 2004 Summer Olympics.
However, on October 8, 2004, it emerged that Waterford Crystal had tested positive for a prohibited substance.
The Federation Equestre Internationale (FEI) ruled that O'Connor must be stripped of his medal and he also received a three month ban from competition. FEI found that he did not deliberately attempt to affect the performance of the horse.
Just four years later fellow showjumper Denis Lynch withdrew from the showjumping final at the 2008 Olympic Games in Beijing four hours before it was due to start after his horse Lantinus tested positive for the banned substance capsaicin.
Lynch claimed the substance was present in a cream he had put on the horse called Equiblock, which is similar to 'deep heat' used on humans.
In October 2008 an FEI tribunal suspended Lynch for three months.
Irish marathon runner Martin Fagan was banned for two years in 2012 by Athletics Ireland following a failed doping test.
The Mullingar native tested positive for EPO at an out of competition test in Tuscon, Arizona, in December 2009.
He admitted that his battle against injury, financial pressure and an ongoing fight against depression, led him to take the performance enhancer in November.