Drugs in Sport: Dwain Chambers may be stripped of the gold medal he won in the 100 metres in the European Championships and the European record he set later that summer if documentary evidence proves he was taking banned drugs in 2002.

The performances of the Londoner, already banned for two years after testing positive for the designer steroid tetrahydrogestrinone (THG) last August, may be re-examined after the publication of emails from the Bay Area Laboratory Co-Operative (BALCO) in San Francisco.

The exchanges between Victor Conte, BALCO's founder, and athletes and coaches, obtained by the US Anti-Doping Agency and published in the San Jose Mercury News, give a rare insight into the shadowy world of doping.

The paper alleged there was regular correspondence between Conte and Remi Korchemny, Chambers' Ukraine-born coach who has been charged along with Conte and two others with being involved in a conspiracy to provide banned drugs to elite athletes.

In one, dated July 2002, Conte referred to an unnamed substance and wrote: "Yes (name deleted) should take a whole pill. (Name deleted) increased from one to one-and-a-half pills before his last race when he ran 9.95. He took one tablet about two hours before the race and another half about 45 minutes before the race for a total of one-and-a-half. About 45 minutes after taking a pill a burst of energy comes and (name deleted) liked the feeling right before the race. Regards Victor."

The name of the athlete is blanked out, but it could be construed to refer to Chambers' performance at a meeting in Sheffield on June 30th, 2002, when he beat the Olympic 100 metres champion and then world record holder Maurice Greene in 9.95 seconds. This is the only performance about that date that matches the time in the email.

It was the second time in three days Chambers had beaten Greene, having also finished ahead of him in Oslo. "There's a new sheriff in town," the Briton said afterwards.

He explained how going to the US to train with Korchemny was behind the improvement. "It's opened my eyes. You think you know about the Americans but you don't really. I have got into their mentality, got inside some of their secrets."

Although the email from Conte to Korchemny does not say the athlete concerned was using banned drugs, other documents among the thousands of emails, ledgers and receipts obtained during the investigation into BALCO could implicate Conte in having supplied elite athletes with illegal substances since 2000.

It is too early to say whether Chambers is the athlete referred to in the email or whether it is evidence that he took banned drugs supplied by BALCO. If there is any such evidence, his case could be referred to the International Association of Athletics Federations, which has the power to investigate old cases and annul results during that period if fresh evidence is presented.

If that happens in the case of Chambers it could lead to a major rewriting of the record books. Among the performances that would be under threat would be his victory in the European Championships in Munich in August 2002 and the European record of 9.87 seconds he set in Paris the following month.

Also affected could be the 4x100 metres relay victories by England and Britain respectively in the Commonwealth Games and European Championships.

Chambers (26), has said repeatedly that he did not knowingly take a banned drug. He is understood to be disillusioned with athletics and he recently appeared on Gordon Ramsay's Hell's Kitchen before walking out.

Even if he were to return to the track towards the end of 2005 he would still be barred from competing for Britain in the Olympics because the British Olympic Association refuses to select athletes who have tested positive for drugs.

Mark Brodie, his spokesman, refused to comment.