Athletics officials have declared the recent World Championships in Japan to have been drug-free.
Lamine Diack has been IAAF president for over seven years
Athletics' governing body the IAAF collected 1132 samples from 976 individual athletes before and during the competition.
French athlete Naman Keita was the only athlete to fail a test but it was out of competition at a team training camp.
"We now have an important year ahead of us as we look forward to Beijing," said IAAF president Lamine Diack.
Keita's positive test for testosterone has been confirmed by the 'B' sample but the IAAF stressed that the control was carried out before the World Championships and was a matter for the French Athletics Federation.
Keita had blamed the positive test on a food supplement he ordered online to help regenerate a sore stomach muscle but he now faces a two-year ban.
The 29-year-old was eliminated in the semi-finals of the 400m hurdles at the World Championships.