The IAAF has provisionally suspended 28 athletes for suspected doping offences at the 2005 and 2007 world championships in Helsinki and Osaka, world athletics' governing body announced on Tuesday.
Most of the athletes concerned have since retired, and none are competing at this month's world championships in Beijing, the IAAF stated.
A total of 32 rogue results from the two championships were uncovered after reexamination of urine samples stored at a World Anti-Doping Agency accredited-laboratory (LAD) in Lausanne.
"The latest scientific breakthroughs in anti-doping technology and analysis have been employed in the reanalysis of these samples to allow us to find previously undetectable substances," explained LAD director Martial Saugy.
The IAAF said re-testing of the 2005 and 2007 samples had nothing to do with the recent allegations of mass doping in athletics.
"The re-analysis of these samples has been ongoing for some time, and was commenced well before the most recent allegations made against the IAAF by the ARD and The Sunday Times," the IAAF stated.
