Backstory to allegations

A look at developments in doping rumors revolving around athletics:

IAAF rejects as "sensationalist and confusing" allegations it failed to take sufficient action against athletes with highly suspicious tests, saying those allegations were "simply false".

IAAF says it has conducted more than 19,000 blood screening tests since 2001, including 8,000 from 2001 to 2009, calling it the most comprehensive and universal blood testing program implemented among sports federations and national anti-doping agencies.