Turning to new technology to uncover previously undetected substances, the IAAF has initiated disciplinary action against 28 athletes after re-tested samples from the 2005 and 2007 World Cham-pionships found 32 adverse doping findings.

World athletics governing body said yesterday it could not name the 28 athletes yet, “due to the legal process”.

“A large majority of the 28 are retired, some are athletes who have already been sanctioned, and only very few remain active in sport,” the body said.

If violations are confirmed the IAAF said it would correct the record books for the 2005 and 2007 World Championships and re-allocate medals as necessary.

The 2005 event was staged in Helsinki, with Osaka, Japan, hosting two years later. The 2015 worlds start in Beijing on August 22.

The IAAF said its re-testing had begun in April, “well before the most recent allegations made against the IAAF by the ARD and The Sunday Times”.

The re-testing took advantage of new testing procedures and the 10-year period now offered under IAAF rules and the World Anti-Doping Code.

“The latest scientific breakthroughs in anti-doping analysis have been employed in the re-analysis of these samples to allow us to find previously undetectable substances,” Martial Saugy, director of the Swiss Laboratory for Doping Analyses in Lausanne, said.