by Justin Rowlatt
BBC Panorama reporter
After previous scandals, the Athens Olympics were presented as a return to the Olympian ideals of integrity and fair play.
But, on the eve of the Games, Panorama showed that there is still corruption at the heart of the Olympic movement.
Buying the Games revealed evidence that the votes of some members of the International Olympic Committee - the private club that controls the Games - are being offered for sale.
During the year-long investigation, we went undercover, posing as consultants acting for clients with business interests in east London who wanted the Games to come to London.
My colleague, Howard Bradburn, and myself were offered enough IOC votes to guarantee the 2012 Games for London.
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We used hidden cameras to film four professional agents who, between them, claimed they could secure 60 IOC votes - a clear majority - in return for payments totalling 10 million euros.
In the climax of the film the Serbian agent, Goran Takac, introduced us to the Bulgarian IOC member, Ivan Slavkov.
We filmed him agreeing to help bring the 2012 Games to London and discussing how the votes of other IOC members could be influenced.
The programme was front-page news around the world even before it was broadcast.
A week before transmission the IOC launched an investigation into the programme┐s revelations and Mr Slavkov was suspended from the IOC and barred from attending the Athens Games.
After Buying the Games was broadcast the more than 5,000 headlines were recorded in the international press. The programme itself was broadcast in many countries.
The IOC was forced to act swiftly.
It's President, Jacques Rogge, was clearly upset by the programme's revelations when he told reporters in the days after transmission: "To say I am disappointed is not enough. I am an angry man because some people are not playing by the rules."
He ordered the IOC's Ethics Commission to investigate Panorama's findings.
Meanwhile all four agents, including Muttaleb Ahmad the director general of the Olympic Council of Asia - the governing body of all amateur sports on the continent - were declared personae non grata within the Olympic movement and banned from all Olympic venues and IOC meetings.
Mr Rogge ordered Olympic officials and bid cities to have no contact with the men.
In addition the IOC wrote to all five bid cities for the 2012 Games asking for details of all meetings and events their teams have attended world-wide over the last year and whom they met.
Panorama provided the Ethics Commission with it's evidence against Mr Slavkov. It also gave the names of more than 30 other IOC members whose votes Goran Takac said he could influence.
In Lausanne on 26th November 2004, the Executive Committee of the IOC recommended that Mr Slavkov be expelled from the from the movement at the next meeting of the IOC.
That vote will take place in July 2005 in Singapore. The same meeting at which the location of the Olympic Games of 2012 will be decided.
The IOC has recommended that Ivan Slavkov be expelled
The real test for the movement now is how it deals with other corrupt members within the organisation.
I questioned President Rogge on this at the Lausanne press conference. I asked if he believed that the IOC is now free from corruption.
He replied that: "Speaking today, no case of corruption is known to the IOC."
When I went on to ask what action was being taken to investigate the IOC members named by Goran Takac, Mr Rogge declared that there was no proof against them and "no substantive evidence".
I attempted to clarify the position, but was told that I was not allowed to ask any further questions. Despite repeated requests for a formal interview with Mr Rogge, this was our only opportunity to discuss our findings.
I had to conclude that the IOC does not intend to take any further action.