It was on the last day of the Championships in the French capital that it was announced that Kelli White, the United States sprinter who had won gold medals in the 100 and 200 metres had tested positive for the stimulant modafinil.

The International Association of Athletics Federations (IAAF), the previous name for the organisation now called World Athletics, disqualified her from the World Championships and stripped her of the gold medals she had won, along with $160,000 (£130,000/€150,000) in prize money.

White claimed she had taken modafinil to combat the fatigue and sleep-inducing effects of narcolepsy but failed to obtain a waiver from the IAAF to be allowed to take the drug. Many former athletes expressed sympathy for White at the time.

But a source in the US suggested that it might be worth me making some inquiries about her coach Remi Korchemny and a nutritionist helping White with her diet and who had prescribed a programme of supplements. That was Victor Conte.

Both were certainly characters with interesting backgrounds.

Korchemny had been born in Ukraine in 1932 and, when he was five years old, his father had been executed by firing squad on charges of sabotage following a dispute at work, while his mother was sent to a forced labour camp for four years, leaving Korchemny to live with his grandparents.

Korchemny had joined the Red Army as an engineer, was introduced to athletics, eventually becoming a coach in 1957. He claimed to have worked with several top sprinters in the Soviet Union, including Valeriy Borzov, winner of Olympic gold medals in the 100m and 200m at Munich 1972, although the runner himself has denied this. In 1975, after years of lobbying to leave the Soviet Union, Korchemny was allowed to move to the United States following brief stays in Israel and Italy.

Conte, meanwhile, was born in California into a family of Italian immigrants. A college dropout, he took up the bass guitar and played in several rock bands, including one called the Pure Food and Drug Act, which proved to be prophetic bearing in mind what was to come later. At the time Conte's nickname was "Walking Fish", due to his unusual way of moving across the stage when he was performing. After leaving the Pure Food and Drug Act, he joined the Tower of Power, an American R&B and funk-based band, that had several Billboard Hot 100 hits.

After leaving the group, Conte’s career had taken a new direction and in 1984 he had set up the Bay Area Laboratory Co-operative (BALCO), a sports nutrition company located in California. He developed his own line of vitamin and mineral supplements, he claimed, to help improve athletes’ performances. His brands SNAC and ZMA - named for its supplement containing zinc, magnesium aspartate, and vitamin B6 - are still available for sale on shelves in the US.

According to Conte, interviewed in a new Netflix documentary Untold: Hall of Shame, BALCO’s operations were completely legal and legitimate until 2000 when he began to dabble in the world of steroids.

With the help of a chemist, Conte developed his own form of anabolic steroids that, it was claimed, would be undetectable in athlete testing. Administered in dropper form under the tongue, he named his steroid “The Clear” for its clear, watery consistency. In order to prevent "The Clear" from changing athletes’ hormone levels, which would reveal their steroid use, he developed a second component that would even out the hormone changes called "The Cream," a topical steroid applied to the skin. It was part of a cocktail of drugs, including modafinil, given to athletes by Conte designed to give them a cutting-edge and evade the testing system. 

Of course, at the time no-one knew anything about this, and Conte just seemed, on the surface, to be a new age pseudo scientist selling supplements that promised more than they could deliver. I had come across Conte earlier in the year when he contacted me and had engaged in a brief email exchange with him before forgetting about him.

A couple of weeks after the World Championships in Paris had finished, the IAAF announced that another American from the event, Chris Phillips, who had reached the final of the 110m hurdles, had also failed a doping test for modafinil.

The same source in the US that I had spoken too earlier pointed me in the direction of Dwain Chambers, the British sprinter who had finished fourth in the 100m in Paris and said I should ask about a positive drugs test involving him.

Earlier in the year, the Londoner had left long-time coach Mike McFarlane to train in America with Korchemny. Under the Ukrainian, Chambers had run 9.96sec for 100m and, though his performance at the World Championships was seen as a disappointment, the European record holder was considered a genuine contender to lift the Olympic title in Athens the next year.

The IAAF and British Athletics, though, were adamant: my information was wrong. There were no more positive drugs tests from the World Championships and certainly nothing involving Chambers. But my source, who worked in law enforcement in the US, urged me to continue chasing Chambers, promising it would be worth it. It became something of an obsession as I began hitting the phones.

The chase then took a strange turn when I received a call from a club athlete in the north of England, who told me that his training group had heard that Chambers had failed a drugs test. The tip-off came, the athlete assured this reporter, from someone who would know. But still calls to the IAAF and UK Athletics drew no information. The IAAF was insistent that it did not understand why I kept called asking about Chambers testing positive for banned drugs and suggested that I should leave it.

Certainly, Chambers and his management group Stellar Athletics were not acting as though they had something to hide. Chambers accepted an invitation from the British Athletics Writers' Association (BAWA) to attend its annual dinner at the Royal Lancaster Hotel, which I helped organise, and Stellar's managing director Jonathan Barnett booked a table for 10.

Then, 10 days before the dinner - attended by the then London 2012 Olympics bid chair Barbara Cassani, UK Athletics' chief executive David Moorcroft and the world record holder Paula Radcliffe - was due to take place, Stellar told the BAWA that Chambers could not attend after all because he was on holiday in the Bahamas. Also, Stellar would not be taking up the table it had booked.

As organisers we were irritated at the failure of one of the country's leading athletes to attend our prestigious dinner, especially as we had already lost the triple jump world record holder Jonathan Edwards after he had been invited to spend the weekend with then Prime Minister Tony Blair.

The Friday after the dinner, the plot began to thicken when the then chief executive of the United States Anti-Doping Agency (USADA), Terry Madden, told reporters during a telephone conference call that the agency had learned about a new designer anabolic steroid called tetrahydrogestrinone, or THG. Madden revealed its production had been traced to BALCO.

Mark Brodie, a spokesman for Stellar, warned me it would be dangerous to make a link between Chambers and Conte and that my newspaper, The Guardian, should be careful before they published the information. This was despite the fact that earlier in the year Conte had contacted The Guardian on Chambers' behalf after the Briton had been linked with Dennis Mitchell, a convicted drugs cheat who had been hired by Stellar as a coach.

What Brodie did not know was that Chambers and his training partners, including White and Philips, had been targeted by the IAAF for an out-of-competition drugs test at the start of August while they were training in Saarbrucken in Germany for the World Championships under Korchemny, after a tip-off from the USADA.

The discovery of THG was so sensitive that only a handful of officials knew that it even existed and were determined that the information would not leak out. The samples were flown back to the International Olympic Committee-accredited laboratory at the University of California in Los Angeles where Don Catlin had covertly established a test for the drug.

There was, however, a delay because of the sheer volume of samples Catlin had to test. But when he got round to analysing Chambers' urine sample, it showed traces of THG.

The IAAF was informed, and they called UK Athletics to break the news. Chambers was contacted a few days later and told of the adverse finding. But even then, he continued to act as if he had done nothing wrong. A few days before his positive test became public Chambers even turned up at Crystal Palace as part of a school sports mentoring programme and happily coached a group of children.

Meanwhile his agent John Regis, the former European 200m champion, asked in calls to Stellar's offices whether Chambers was involved in the THG scandal, but he gave a blunt denial. But while Chambers was signing autographs in South London, a source close to the case revealed details of his positive test to The Guardian.

I was preparing to board a flight to Athens to interview Gianna Angelopoulos-Daskalaki, head of the Organising Committee for the 2004 Olympics, at the time I received the confirmation I had been chasing for nearly two months. I hastily got my bags offloaded the flight and started making calls.

When Brodie was contacted, he said that he would need to contact Chambers. He rang back six minutes later and threatened legal action if the story ran. By then it was too late. The story ran and Chambers’ promising career was ruined.

Once I had started pulling the thread, it seemed never ending. Other big names in athletics were dragged into the scandal, including the sport’s golden girl Marion Jones, winner of five Olympic medals at Sydney 2000, including three gold, and her partner Tim Montgomery, the world record holder for 100m.

Montgomery admitted in an interview with Untold: Hall of Shame that he had taken anabolic steroids from Conte. But Jones, who split with Montgomery after the scandal became public, still denies having ever knowingly used performance-enhancing drugs.

Jones served six months in jail in 2008 for perjury and is the only athlete to serve time in the BALCO case. She also had to return all five of her Olympic medals. Montgomery’s 2002 world record in the 100m was disqualified in 2005.

Victor Conte? He spent four months in prison and four months under house arrest for his part in the steroids scandal that implicated one of America’s favourite baseball players Barry Bonds. But he is filmed in Untold: Hall of Shame driving a 2023 Bentayga S that cost $275,000 (£220,000/€250,000) after claiming he made $80 million (£63 million/€74 million) from sales of ZMA and other supplements.

"Should I send the feds [FBI] a thank-you card?" he asks with a grin in the film. "They might have made me millions of dollars."

During the film, which lasts nearly 80 minutes, Conte, now 73, cries as he expresses remorse at the athletes he helped had suffered and seen their careers and reputations ruined.

But perhaps something Conte says earlier in the film is even more telling. When reflecting on the edge he provided to athletes who employed him, he did not try to hide the pleasure, the notoriety and plaudits it had bought him. 

"When Marion Jones hit the finish line and won the gold medal, when Barry Bonds hit all these home runs, you know, any of these great accomplishments, those are things that I’ll always be proud of," he says.