Welsh 800 metre runner Gareth Warburton has been provisionally suspended from all competition after being charged with an anti-doping offence.
The 32-year-old had been due to compete at his third Commonwealth Games in Glasgow this month before being informed of his suspension.
A statement from UK Athletics read: " UK Athletics has today announced that 800m athlete Gareth Warburton has been provisionally suspended from all competition after being charged with committing anti-doping rule violations under UK Athletics Anti-Doping Rules (presence of prohibited substances).
"The athlete has the opportunity to respond to the charges against him, and to have those charges determined at a full hearing before the National Anti-Doping Panel."
Warburton narrowly missed out on a medal at the Delhi Games in 2010 when he finished fourth in the 800m behind Kenyan trio Boaz Lalang, Richard Kiplagat and Abraham Kiplagat.
He holds two medals from the European Indoor Championships and was also part of the Great Britain team at London 2012, where he failed to qualify from his first round heat.
Team Wales Chef de Mission Brian Davies said: "Team Wales can confirm that one of the competitors selected for the Glasgow 2014 Commonwealth Games has been provisionally suspended after being charged with committing an anti-doping rule violation. As a result Gareth Warburton will no longer be able to compete at the Games.
"As the athlete is presumed innocent unless and until the charges brought against him have been upheld it would be inappropriate for us to comment further.
"Team Wales is committed to providing athletes with the necessary education required to ensure we compete as clean athletes at a clean Games, and have worked closed with UK Anti-Doping in the build up to Glasgow 2014."