London, UK: The world athletics governing body blocked the publication of a report that showed as many as a third of the world’s top athletes admitted using banned performance-enhancing techniques, The Sunday Times reported.

The authors of the report told the British newspaper that the International Association of Athletics Federations (IAAF) blocked publication of the study, which was carried out four years ago.

‘The IAAF’s delaying publication for so long without good reason is a serious encroachment on the freedom of publication,’ the University of Tuebingen in Germany, which carried out the research, said in a statement according to the paper.

Researchers from the university were given access to elite athletes at the 2011 world championships in Daegu, South Korea and concluded in their research that between 29 and 34 per cent of the 1,800 competitors at the championships had violated anti-doping rules in the previous 12 months.

‘These findings demonstrate that doping is remarkably widespread among elite athletes, and remains largely unchecked despite current biological testing programmes,’ the report concluded.

The study was funded by the World Anti-Doping Agency (WADA), but they gave the IAAF power to veto publication in exchange for access to the athletes at Daegu, WADA confirmed to The Sunday Times on Friday.

In the months after conducting the study, the researchers were told to sign a confidentiality agreement to prevent them speaking out about the findings but they have now criticised the IAAF for suppressing the report.

‘The IAAF is blocking it. I think they are stakeholders with Wada and they just blocked the whole thing,’ lead author Rolf Ulrich told The Sunday Times.

Some of the key figures from the report were leaked in the United States in 2013 but the IAAF continued to prevent full publication.

In early August, the newspaper published a separate report on a leaked database of 12,000 blood tests from 5,000 athletes that revealed ‘extraordinary’ levels of doping, and sent shock waves through the sporting world.

The IAAF hit back at the allegations describing them as ‘sensationalist and confusing’.