Thousands of leaked blood tests obtained by several news organizations allege that one-third of Olympic and World Championship medal winners in long-distance running events are suspected of blood doping.

Thousands of leaked blood tests obtained by several news organizations allege that one-third of Olympic and World Championship medal winners in long-distance running events are suspected of blood doping.

The Sunday Times, a British newspaper, and German broadcaster ARD/WDR both published reports on the data Sunday. The BBC has also seen the data.

The media outlets received 12,000 test results from 5,000 athletes and concluded that roughly one third of the medal winners in the highest-level distance events have recorded suspicious tests. A total of 146 Olympic and World Championships medals (including 55 gold medals) between 2001 and 2012 were won by runners who recorded suspicious tests.

Out of the 5,000 athletes tested, 800 had tests that were “highly suggestive of doping, or at the very least abnormal,” anti-doping expert Robin Parisotto concluded.

One expert who examined the data compared the pervasiveness of blood doping in distance running to the height of the doping scandal in cycling.

The IAAF, track and field’s international governing body, briefly addressed the allegations Sunday and said it was “preparing a detailed response.”

“The IAAF is aware of serious allegations made against the integrity and competence of its anti-doping programme,” the statement read.

The reports were based on “private and confidential medical data which has been obtained without consent,” the IAAF added.

The 2015 World Championships begin later this month in Beijing.

- Dan Gartland