London: Olympic athlete Rhys Williams is set to compete again after a serving a ban for a positive drugs test, the 400 metre hurdle runner announced Sunday.
The former European champion served a four-month ban after testing positive for a banned substance last year.
Meanwhile, another Wales and Great Britain athlete, 800m runner Gareth Warburton, has had his ban reduced to six months having failed a test in June.
Warburton`s case also involved the same contaminated supplement, an energy drink which was found to contain anabolic steroid metabolites.
However, both athletes have been cleared of knowingly cheating by UK Anti-Doping and the National Anti-Doping Panel. Now the pair have had their bans backdated to the time of their provisional suspensions in July.
In a statement released on his website on Sunday, Williams said he was looking forward to competing at the 2015 World Championships in Beijing in August.
"I have always maintained that I have never intentionally taken any banned substance and following today`s decision, I am pleased that both UK Anti-Doping and NADP agree with this," said Williams, 30, the son of Wales rugby great JJ Williams.
"I carried out all necessary checks within my power before consuming the product, unfortunately in this instance I have been severely let down by a manufacturing company," he added.
"However, I accept that responsibility for the supplements I take rests with me and I accept the four-month ban.
"This has been an absolutely devastating situation to have found myself in and missing out on the opportunity to represent Wales at the Commonwealth Games (in Glasgow last year) was particularly hurtful."
Williams, who said he hoped younger athletes might learn from his experience, added: "I am looking forward to getting back on to the track, with my focus now firmly on gaining selection for the World Championships in 2015."
Williams`s legal team were successful in arguing that, although the positive test came before the introduction of the new World Anti-Doping Code on January 1, he should benefit from new powers of discretion in tribunal cases where there is no significant fault or negligence on the part of the athlete.
Colin Gibson, a partner at lawyers Charles Russell Speechlys LLP who represented Williams, said in a statement: "The decision handed down by the tribunal is significant in that it is an early application of the 2015 WADC sanctions to a case under the previous rules, and because it is likely to be a benchmark for future contaminated supplement cases."