Olympic heptathlon champion Jessica Ennis-Hill called on athletics' world governing body and the World Anti-Doping Agency to address a report in the Sunday Times which appears to show cheating has taken place on a vast scale in the sport during the last decade.
The newspaper says it, along with the German broadcaster ARD/WDR, has had access to a database containing more than 12,000 blood tests from 5,000 athletes and reveals "the extraordinary extent of cheating by athletes at the world's most prestigious events".
The data, which belongs to the International Association of Athletics Federations (IAAF) but was released by a whistleblower, has been analysed by two leading anti-doping experts for the Sunday Times - scientist Robin Parisotto and exercise physiologist Michael Ashenden.
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According to them, the leaked data reveals that more than a third of medals - including 55 golds - that have been awarded in endurance events at the Olympics and World Championships between 2001 and 2012 had been won by athletes who have recorded suspicious tests. The newspaper claims none of those medals have been taken away by the authorities.
Ennis-Hill lost out on gold at the 2011 World Championships to Russian athlete Tatyana Chernova, who has since served a two-year doping ban.
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The 29-year-old from Sheffield told the Sunday Times: "It is never good to hear of new possible doping offences in my sport, but if we are to stop a few athletes thinking cheating is acceptable, we have to explore all information that comes to light, however damaging it is for the sport as a whole.
"Like so many other clean athletes I put my faith in the system operated by the IAAF and WADA and focus on training.
"I very much hope both organisations can respond to the latest allegations quickly so athletes and fans alike can carry on with confidence believing that progress is being made in tackling doping in our sport."
Lord Sebastian Coe, an IAAF vice-president and a candidate for the presidency of the organisation, has called for the sports body to put more into the fight against drugs cheats.
Earlier this year, he said: "The gap between the positive test and sanction must be reduced. It would cost more money but I'd find it. I'd have to.
"It would remove the conspiracy theories."
British 800 metres specialist Jenny Meadows believes in the past she has been cheated out of at least three medals.
HARD WORK UNREWARDED
She has now admitted her devastation at the apparent evidence of blood-doping presented by the Sunday Times, and told the newspaper: "When I'm training I go down to the track and almost kill myself on a daily basis. It's not pleasant.
"I'm trying to get the most out of my body in a natural way. You really have to have a high pain threshold.
"People who are blood-doping don't have to go through that the same way. It's a short cut. That is really demoralising.
"It makes you not want to get up in the morning and work so hard.
"You want to know every time you stand on that line you are competing on a level playing field. You don't want to think that someone hasn't gone through those gruelling sessions and are just out to rob you of your result."
TIME FOR CHANGE
Five-time Olympic rowing champion Sir Steve Redgrave hopes that "drugs are not the focal point of the Rio Olympics" next summer.
The 53-year-old, who also won three Commonwealth Games gold medals and nine World Rowing Championships golds during his career, told the Mail on Sunday: "I sincerely hope drugs are not the focal point of the Rio Olympics.
"However, you find that the Olympics attracts greater media coverage and the Games of course has a history of such issues.
"When the whole world is there, it is a very good time to expose drug-taking. Sadly, it remains a part of sport.
"There have always been cheats, there have always been those who have sought an advantage.
"The powers that be in sport, in this instance the World Anti-Doping Agency, need to be one step ahead of this rather than one step behind as they have been at times.
"Sport should be about fair play and competition should be on a level platform."
British middle-distance runner Andrew Baddeley was beaten by suspect runners during a major event and he admitted the news of the latest findings comes as no real shock.
He said: "In an awful way, nothing surprises me any more.
"Doping now seems to be so widespread that it's difficult to prove you are clean.
"Look at what happened to Chris Froome in the Tour de France. He was being accused of cheating when there wasn't a shred of evidence to support it.
"The IAAF need better funding and better resources to tackle this problem or else nothing is going to change."