Five-time Olympic champion Ian Thorpe faces a hearing of the Court of Arbitration for Sport before he can clear his name of doping.
Thorpe said hearing about his test result was "gut-wrenching"
Thorpe, now retired, returned a drug test last May with abnormal levels of testosterone and leutenising hormone. He denies any wrongdoing.
The CAS, which will not comment on the case, will rule on whether Thorpe's sample constitutes a doping violation.
Both substances are on the banned list but are naturally produced by the body.
Swimming's governing body, Fina, said it "considered the findings of this sample as an adverse analytical result".
It said it had lodged an appeal with the CAS "with the aim of clarifying the issues surrounding this case".
The Australian Sports Anti-Doping Authority has been under fire for the length of time it was taking over analysing Thorpe's test.
But its chairman, Richard Ings, denied his organisation had closed Thorpe's case.
Ings said ASADA was "working through the procedures outlined in the World Anti-Doping Agency (WADA) Code and the international standard for testing for unusual readings of these naturally occurring substances".
It wanted to ascertain "whether there may be a pathological or physiological explanation for these unusual readings of naturally occurring hormones".
The delay in handling Thorpe's case is a reflection of the difficulty in analysing testosterone cases, which pose anti-doping authorities some of their most complex problems.
When something like this happens, you get tarnished with a kind of black spot
Athletes are tested initially for the ratio of testosterone to epitosterone in their bodies, with 4:1 being the maximum allowed limit.
Any ratio above 6:1 is considered a clear violation, but any level in between falls into a grey area that requires further investigation.
The first level of further analysis is a carbon isotope ratio mass spectrometry analysis, which establishes whether the testosterone was exogenous - or not naturally manufactured in the body.
Passing that test technically means a negative doping result, but some in world sport feel it should be regarded as inconclusive because of the fear of cover-ups.
That fear is rooted in a concern athletes are using low levels of testosterone, or something to stimulate its production.
The apparent provision of an athlete's name to the media when it should have been kept confidential is unacceptable
Leutenising hormone, for which there is no maximum limit specified by anti-doping authorities, is one of the substances that stimulates the production of testosterone.
The CAS now has to decide whether Thorpe's findings can be naturally explained, as he insists they can, or whether another explanation is more probable.
The difficulty in establishing guilt in such cases has led to calls for anonymity until a final verdict is reached.
The World Anti-Doping Agency said in a statement: "Wada is especially shocked that the name of an athlete was apparently given to the media while no adverse analytical finding has been determined at this point."
The statement added: "The apparent provision of an athlete's name to the media when it should have been kept confidential is unacceptable."
In the meantime, Fina, Swimming Australia, and ASADA all said they would launch investigations into how information about Thorpe's case came to be leaked to the French newspaper L'Equipe, which first broke the story.
Thorpe said he found out about the test only on Saturday morning - after it became public.
"I didn't know how to react," Thorpe said. "I was physically shaking. I didn't understand it. It's gut-wrenching. When something like this happens, you get tarnished with a kind of black spot."