In the run up to the Beijing Olympics, Matt McGrath sets out to expose corruption, drug use and cover-ups at the highest levels in sport in this two-part investigation.
Part 1 - Testing Times
In the first part of this investigation, Matt hears claims that chaos is reigning in the world's anti-doping systems ahead of the Beijing games.
With 10,000 athletes set to compete in next month's event, more than 4,500 drug tests will be carried out, that's the highest number ever to be tested at a sporting event.
However, according to one expert, there are hundreds of suspicious samples lying around in anti-doping laboratories which they are unwilling or unable to declare positive.
A popular drug that is being used by many athletes across the board is Erythropoietin (EPO).
EPO is a hormone that is naturally produced by the kidneys.
But it can be artificially produced to improve the performance of athletes or cyclists by injection.
EPO stimulates red blood cell production and helps to increase endurance.
The more red cells there are in your body, the more oxygen that can be delivered to the muscles.
This delays the onset of fatigue, meaning an athlete can run or cycle harder and for longer.
However, the use of this performance enhancer is proving particularly difficult to stop, as there are now dozens of new versions on the market and, as sources reveal exclusively to the BBC, the drug has, in their experience, never been more widely abused.
There are also concerns about the reliability and competence of some laboratories.
The World Anti-Doping Agency has also been criticised for not having an effective criteria for testing for EPO.
Matt also explores the remarkable story of the highly-rated academics in Germany who are now facing trial on charges of helping athletes to cheat.
With the Olympic Games in Beijing less than a month away there are many who believe that sport has too much to loose to ever be drug free.
Listen to Matt as he investigates if doping is in the blood of sport.
First broadcast on 21st July 2008.