RPA Rugby Director David Barnes said, "This was the correct decision and we are relieved that an innocent player has not had his reputation unnecessarily damaged. For Eifion to have had this hanging over him since the test took place in June 2012 is unacceptable in professional sport.
"As part of the joint RPA, RFU and Premiership Rugby Anti-Doping Board the RPA is fully committed in the fight against cheating in sport. In addition to a comprehensive testing programme all Aviva Premiership players must complete a mandatory annual Anti-Doping education programme to remind them of their responsibilities as professional athletes as well as the potential health risks that can arise as a result of taking banned substances.
"In this case, as the panel have agreed, there was no intention on the player's part to enhance his sporting performance and he has fully co-operated with the investigation to prove his innocence."