LONDON (REUTERS) - Disciplinary action has been initiated against 28 athletes after the IAAF retested samples from the 2005 and 2007 World Championships, and found 32 "adverse findings".
World athletics' governing body said on Tuesday it could not name the 28 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.
"The IAAF is provisionally suspending them and can confirm that none of the athletes concerned will be competing in Beijing."
The 2005 event was staged in Helsinki, with Osaka, Japan, hosting two years later. The 2015 World Championships start in the Chinese capital on Aug 22.
The IAAF said its retesting had begun in April "well before the most recent allegations made against the IAAF by the ARD and The Sunday Times".