Cesar Cielo, the world champion, can defend his sprint freestyle titles at the forthcoming World Championships in Shanghai after the Court of Arbitration for Sport (CAS) reaffirmed the Brazilian swimming federation's decision to warn and not suspend him following a positive drug test.
Cielo, who won the 50 metres and 100m freestyle titles in Rome two years ago, was one of four Brazilian swimmers to test positive for the banned substance furosemide at the Maria Genk Trophy in May.
The Brazilian Aquatic Sports Confederation had accepted Cielo's explanation that his normal supplements had been cross-contaminated and warned the four swimmers rather than impose a ban of up to two years.
However, the governing body, Fina, appealed to CAS for an urgent hearing, and called for three-month bans for Cielo, Nicolas dos Santos and Henrique Barbosa as well as a one-year suspension for Vinicius Waked, given that it was his second offence.
With the pool competition in China beginning tomorrow, a speedy resolution was essential. The hearing was held yesterday, and the decision drew a strong reaction.
Roland Schoeman, a triple world champion, tweeted: "Fina and the CAS have done a great disservice to the world of swimming & set a dangerous precedent."
Fina, though, are bound to accept the decision, and executive director Cornel Marculescu said: "I respect the decision of the CAS; they are the last legal resort in sports. I'm not satisfied but I think we have done our job."
Cielo was represented by the lawyer Howard Jacobs who said: "The arbitrators agreed there was no intent to cheat and no performance enhancing. They accepted the explanation that the supplements were contaminated. It's good now that the arbitrators can distinguish from case to case when an athlete tries to cheat."
Jacobs also represented the US swimmer Jessica Hardy in her successful appeal to the International Olympic Committee, which cleared her to compete at the 2012 Olympics.
Hardy was given a one-year ban after testing positive for clenbuterol at the 2008 Olympic trials. She claimed to have unknowingly taken it in a nutritional supplement. CAS rejected an appeal by the World Anti-Doping Authority, to double her ban to two years.
However, the case of Albert Subirats highlights inconsistencies in doping punishments. The Venezuelan was handed a one-year suspension under the "whereabouts" rule, which requires athletes to keep anti-doping authorities informed of their location.