British sprinter Nigel Levine has been handed a provisional suspicion over a failed drugs test.
The 28-year-old Olympian allegedly tested positive for the banned asthma drug clenbuterol in December.
Levine will be offered a UK Anti-Doping hearing to defend himself.
He has not competed since January 2017, after breaking his pelvis in a motorcycle crash in Spain.
Clenbuterol is on the World Anti-Doping Agency's prohibited list because it is deemed a performance-enhancing drug and can induce weight-loss.