MacLeod: Escaped ban on Monday
The World Anti-Doping Agency (WADA) have revealed they could appeal the decision that allows Scotland international Scott MacLeod to resume playing.
The Scarlets lock, who has 21 caps for his country, escaped a two-year ban on Monday for having an elevated level of testosterone in his body.
The re-test of a urine sample was found to contain traces of alcohol that MacLeod claimed to have consumed the night before he was originally tested, thus accounting for the raised levels of the naturally-occurring hormone.
The 29-year-old was therefore given permission to resume training with his club more than a month after being suspended from all rugby.
But WADA will now ask UK Sport - who carried out the testing - and the Scottish Rugby Union for a written copy of the decision to clear MacLeod in order to determine whether it complies with their code.
If not, they will then decide whether to take the case to the Court of Arbitration for Sport.
WADA have confirmed they were aware "high alcohol consumption" could lead to elevated testosterone/epitestosterone levels.
They further said anti-doping organisations were already permitted to take this into account when deciding whether an athlete had a case to answer.
Yet, citing WADA guidelines, UK Sport explained on Tuesday they did not test for alcohol as standard because it is not on the list of prohibited substances.
They only re-tested MacLeod's B sample when the player remembered he had been out celebrating his wife's pregnancy the night before the original test in January.
MacLeod - who wants alcohol to be tested for as standard - his club and the SRU have all called for changes in the handling of testosterone cases.
And WADA have revealed they are planning to emphasise the impact of alcohol in a technical document being prepared for their executive committee.
But speeding up the investigative process is unlikely to happen, with UK Sport forced to carry out a series of tests across a number of months before being
able to determine whether elevated testosterone levels are due to doping.
UK Sport communications officer Lee Taylor said: "In terms of the timeframe, testosterone is one of the most complex stimulants we can test for.
"There really does have to be the most comprehensive check on whether it's naturally occurring or whether it's the result of doping.
"That always ensures the process is slightly longer. It takes time to make sure there aren't any inconsistencies.
"We just have to be very careful in ensuring we get everything right from this end before we proceed with determining whether there's a case to answer."
Taylor added that, as well as the scientific evidence, UK Sport took into account witness statements supporting MacLeod's claim he had been out drinking the night before the original test.
He said: "Even though Scott's explanation was he was out the night before, there was still a case to answer.
"He still needed to prove that was indeed the case. It's not just accepted as read."

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