Secret data revealing the extent of cheating by athletes at the world’s most prestigious events was revealed by The Sunday Times Insight team, after the biggest leak of blood test data in sporting history.

Insight and German broadcaster ARD/WDR were given access to a database containing more than 12,000 blood tests from 5,000 athletes, including many household names from across the world.

The blood-doping data reveals that a third of medals, including 55 golds, have been won in endurance events at the Olympics and world championships from 2001-2012 by athletes who have recorded suspicious tests – yet the authorities have failed to take away any of the medals.

The Insight team working on the story was George Arbuthnott, Jonathan Calvert, David Collins and Bojan Pancevzski. The data team comprised Stefano Ceccon, Neil Johnston and Megan Lucero.

The data in the files has been kept under lock and key for years at the International Association of Athletics Federations’ (IAAF) Monaco HQ, but released by a whistleblower seriously concerned about its content.

Shocked scientist Robin Parisotto, who regularly reviews athletes’ blood tests, said:

Never have I seen such an alarmingly abnormal set of blood values…so many athletes appear to have doped with impunity.

The revelations include:
• More than 800 athletes recorded blood test results described as ‘highly suggestive of doping or at the very least abnormal’
• A top UK athlete is among seven Britons with ’suspicious’ blood scores
• Ten medals at the London 2012 Olympics were won by athletes who have had dubious test results
• Twenty-one athletes recorded blood values so extreme that they risked heart attacks or strokes
• Star names such as Mo Farah, Jessica Ennis-Hill and Usain Bolt emerge as clean with no abnormal results
• More than a third of the world’s fastest times in endurance events were achieved by athletes whose tests have triggered suspicion.