The world governing body of athletics is denying it tried to suppress revelations that a third of top athletes had admitted to doping.

The International Association of Athletics Federations (IAAF) allegedly stopped the study, carried out in 2011, from being published and prevented its authors from speaking about it.

Researchers found that between 29% and 34% of 1,800 competitors at the world championships in Daegu, South Korea, had confessed to using banned techniques in the previous 12 months, The Sunday Times reported.

The University of Tubingen in Germany, which led the research, is quoted in the newspaper as saying: "The IAAF's delaying publication for so long without good reason is a serious encroachment on the freedom of publication.

"These findings demonstrate that doping is remarkably widespread among elite athletes, and remains largely unchecked despite current biological testing programmes."

When asked about the study being blocked, lead author Rolf Ulrich added: "The IAAF is blocking it. I think they are stakeholders with WADA (World Anti-Doping Agency) and they just blocked the whole thing."

The IAAF told the newspaper: "Discussions are ongoing with the research team and WADA regarding publication."

It comes after WADA announced it would launch an investigation into widespread doping allegations against international athletes.

The allegations came from a TV documentary by German broadcaster ARD entitled "Doping - Top Secret: The Shadowy World of Athletics".

ARD and the Sunday Times obtained a leaked database belonging to the IAAF which contained more than 12,000 blood tests from around 5,000 athletes in the years 2001 to 2012.

Their investigation resulted in claims that more than 800 athletes had suspicious results which were not followed up by the IAAF.