大象传媒

Mariem Selsouli gave a sample which contained a banned diuretic shortly after running the fastest time this year over 1500 metres in Paris earlier this month. She has become one of more than a hundred athletes worldwide who have been caught in the last six months.

The anti-doping operation at this Olympics will be the most rigorous in history. There are new ways to detect banned substances like human growth hormone and synthetic testosterone which have previously dipped beneath the radar. But despite the advances, the Director General of the World Anti-Doping Agency has expressed caution. David Howman feared as many as one in ten athletes at the Games could be cheating the system. And he said the sophisticated dopers are difficult to trap.

WADA said intelligence gathering had become key in identifying potential cheats and that individual athletes have been targeted. Samples taken in London will be kept for the next eight years. The message to those who want to use banned products was they would never be able to rest at ease. Although the International Olympic Committee has been criticised for not re-testing the batch from the 2004 Games in Athens until recently.