Kuala Lumpur: The head of world athletics vigorously defended the IAAF’s anti-doping record on Monday, as global sporting bodies called for a thorough probe of the latest allegations to plunge international sport into crisis.

Britain’s Sunday Times newspaper and Germany’s ARD/WDR broadcaster reported on Sunday they had obtained secret data from the International Amateur Athletics Federation, supplied by a whistleblower, that indicated suspicions of widespread blood doping in athletics.

“There are allegations made, no evidence. We want to look into them seriously because to say that in athletics between 2001 and 2012 we did not do a serious job with tests is laughable,” IAAF president Lamine Diack said in response to the reports.

Coming only weeks before track and field’s showpiece event, the reports claim endurance runners suspected of doping had been winning a third of the medals at Olympic Games and world championships in that period.

The allegations are the latest setback to tarnish the multi-billion dollar world of sport after the scandal at soccer’s global governing body, Fifa.

Athletics are a central part of the Olympics, the only sporting event that rivals soccer’s World Cup in scale and which collects billions of dollars from sponsors like Coca-Cola, Panasonic, Visa and McDonald’s.

Medals won could be affected if any cases of doping were subsequently unearthed using newer testing techniques that did not exist at the time.

“I do not know what we are dealing with,” Senegal’s Diack said. “It is possible if we discover with new techniques that someone doped etcetera, etcetera then yes, otherwise no. But I laughed when I read between 2001 and 2012 IAAF did not do the work,” he said.

Arne Ljungqvist, the head of the IOC’s medical commission, had worked hard to combat doping in that period, Diack said.

The reports come weeks before a new IAAF president will be elected, with Britain’s Sebastian Coe and Sergey Bubka of Ukraine bidding to replace the retiring Diack.

Shaikh Ahmad Al Fahad Al Sabah, one of the most influential figures in world sport, appeared sceptical about the timing of the allegations before that election.

The Kuwaiti, who is the head of the Olympic Council of Asia and the Association of National Olympic Committees, said: “I’m hearing all those news (but) I don’t have the big picture.

“If there is some mess I hope it will be solved by the mechanism of the governance and anti-doping. If not, related to election time I will understand it.”

The IAAF noted that the reports were based on confidential information obtained without permission.

A heavy preponderance of the “abnormal” results were from Russian athletes, according to the media reports. Russian sports minister Vitaly Mutko has said the allegations had “nothing to do with Russia” and that they reflected a power battle before the IAAF leadership vote.

Russia accounted for 415 abnormal tests, followed distantly by Ukraine, Morocco, Spain, Kenya, Turkey and others.

“A remarkable 80 per cent of Russia’s medal winners had recorded suspicious scores at some point in their careers,” the Sunday Times said.