Bulgarian athlete Daniela Yordanova has been barred from the Olympics after failing an out-of-competition doping test in Sofia on 13 June.
A potential 1,500m medal contender, 32 year old Yordanova had been due to fly to Beijing today, but a positive test for Testosterone means she is not wanted and will not be taking part.
During the first six days of competition, 2,200 tests were carried out with three contestants testing positive and being sent packing.