Dwain Chambers admits using seven-drug cocktail

The disgraced British sprinter tested positive for the designer steroid THG in August that year and received a two-year ban.

But it has now been revealed Chambers was also using a human growth hormone, a blood-boosting drug, insulin, a testosterone cream, a drug called Modafinil used to promote alertness and a synthetic form of thyroid hormone.

Chambers, 30, met UK Sport's anti-doping boss John Scott today as part of his campaign to come clean and still hopes to gain a place on the British Olympic team.

Scott said: "We had a constructive and positive meeting and see it very much as the starting point of what we hope will be an ongoing relationship.

"Through the letter which Dwain handed to us, he has provided a detailed account of his doping programme which highlights the level of sophistication that goes on in these systematic regimes.

"It is through this sort of information that we are able to better understand both the mindset of why athletes choose that path and the network that sits behind them."

Meanwhile, Chambers is considering whether to challenge his lifetime Olympic suspension by taking legal action against the British Olympic Association in the High Court. Chambers returned to track action in 2006 and re-established himself as the country's top sprinter by claiming the 60metres silver medal at this year's World Indoor Championships.

UK Athletics performance director Dave Collins admitted that if the BOA ruling is overturned there would be little to prevent him competing in Beijing.

"If he is reinstated, then he is eligible and we should consider him," said Collins.