Allan Wells admits that he is not surprised that another leading light has been dragged into the shadows and accused of doping. Maurice Greene, the two-times Olympic champion, has denied reports that he once spent $40,000 (about £20,000) on drugs, but Wells revealed that he has heard damning allegations about a string of other leading stars.

“In the last few months, I've been told things about certain athletes and you could not get any bigger than these names,” Wells said. “These things come to me as an ex-athlete.” Wells, the Scot who won the 100 metres at the 1980 Olympics, was speaking as athletics headed towards potential meltdown with both sides in the perjury trial of Trevor Graham, the American sprint coach, preparing to name and shame high-profile drug cheats. Ángel Guillermo Heredia, a prosecution witness, has named 24 athletes allegedly involved in doping, including a dozen with 26 Olympic medals between them. So far, Greene is the only name to be leaked. “My name's come up in something and it's not true,” he said.

Wells, while distancing himself from the Greene reports, said that there had long been suspicion of some American athletes. “Believe me, the difference between running 10 seconds for the 100 metres and the times some people have done is enormous,” he said. “These are superhuman performances. There were question marks when I came through, but my results look feeble now.”

The 100 metres has certainly moved on. Wells won gold in Moscow in 10.25sec, but 50 athletes ran inside 10.15 last year, including six Britons. What astounds Wells is the way runners now keep their form going throughout an entire summer. “I know the work I put into it and I know how hard it was psychologically,” he said. “I was totally knackered at the end of the season - it was like a boxer, you're so focused and concentrated that you can only last so long. Now they break records at the end of the season. That's incredible.”

Wells added that he is disillusioned with the ineffectiveness of dope testing. While the IAAF this week confirmed that none of the 127 tests at last month's World Indoor Championships had been positive, that is no cause for celebration because Marion Jones passed 160 tests, but is in jail after lying about her drugs use.

“I am disillusioned that there is still no effective test for growth hormone,” Wells said. “I know a British scientist says he has had a test for years, but it has not been used. I don't know if that is down to politics or if there's a hidden agenda, but we need to work together to deal with this. We have a long, long way to go before the public feels athletics is clean. There needs to be collective will and I'm not sure there is.”

One of the Britons to beat Wells's gold medal-winning time last year was Mark Lewis-Francis, but he will almost certainly miss the Olympics after a scan revealed a serious Achilles problem. The 25-year-old, who looked like a superstar in waiting when he ran 9.97sec as a teenager, will have an operation. Lewis-Francis anchored the Britain 4x100 metres relay team to gold in Athens four years ago, holding off the challenge of Greene, but was stripped of his European indoor 60 metres silver medal after testing positive for cannabis in 2005. UK Athletics gave him a warning after he claimed that he ingested the drug passively and the BOA lifted its ban.

His misfortune will be noted by Dwain Chambers, who is still to make a decision on whether to mount a legal challenge to his BOA life ban. Wells says he will walk away from helping the BOA if Chambers runs in Beijing because of the disgraced sprinter's suggestion that you could not win gold without doping.

The United States has taken the lead in exposing drug cheats through federal investigations and a dozen elite athletes have signed up for extra blood and urine tests to prove that they are clean. Allyson Felix, the sprinter, who won three gold medals at the World Championships, said of Project Believe: “Whatever I can do to prove I'm clean, whatever it takes, waking up or driving at five in the morning, I want to do it.”

Paul Tergat, the former marathon world record-holder, has joined Haile Gebrselassie in pulling out of the Olympic marathon. The 38-year-old Kenyan said that he is not fit enough after spending four months on a military course.

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