Allegations that the International Association of Athletics Federations blocked the publication of a study showing widespread doping among athletes at the 2011 World Championships have been denied by the world governing body.

The Sunday Times said the IAAF vetoed a survey showing up to a third of top athletes at the championships in South Korea confessed to using banned performance-enhancing techniques in the previous 12 months.

It is the latest doping allegation to hit the governing body, which has come under attack amid allegations - which it strongly contests - that it is not doing enough to clean up the sport.

"The IAAF has never vetoed publication of this article," it said in a statement on Sunday.

The supposed blocked survey shows up to

The organisation allegedly stopped a study, which was carried out in 2011, that shows that a third of top athletes admitted cheating, from being published, and prevented its authors from speaking about it.

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

Researchers compiled the information from athletes who competed at the world championships in Daegu, South Korea, four years ago. The results reportedly show that 29-34% of the 1,800 competitors had confessed to using banned performance-enhancing techniques 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," they concluded.

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

The IAAF is quoted as saying: "Discussions are ongoing with the research team and WADA regarding publication."

The IAAF continued to say the study was a "social science based survey" conducted by the World Anti-Doping Agency and a team of researchers at the athletes' village at the Daegu World Championships.

The IAAF, which said it answered concerns about the study when it was raised on a German television programme in 2013, claimed the article was rejected for publication by a scientific journal, having been submitted without its knowledge.

It also revealed it had "serious reservations" over the interpretation of the results received in the survey which were confirmed by "high-profile experts in social science" who reviewed the article for it.

"The IAAF submitted those concerns to the research group, but has never heard back from them," the governing body said.

The IAAF said: "The purpose of the study was to assess the reliability of potential new methods of evaluating the prevalence of doping in sport using more of a social science approach (randomised-response survey).

"The survey was intended to be extended to multi-sport events and no publication was ever evoked. In fact, the survey was only ever repeated once, with a revised methodology, at the Pan-Arabic Games where mainly athletes were interviewed."