Richardson targets gold in Athens

He also argued his innocence over the drug allegations and said he was convinced he would win gold at the Athens Games to make up for the bitter disappointment of missing this year's Olympics.

Richardson said: "This is not sour grapes, but that 400m final in Sydney was incredibly soft, except for Michael's winning run.

"I haven't been able to bring myself to watch much of the Olympics.

"I saw the 400m final just by chance at home and found the experience heartbreaking. I hope I don't sound conceited, but that final left me gutted because I know I would have stood a fantastic chance of winning a medal. Before the Games, Michael was the only athlete consistently beating me."

Richardson found it particularly painful that some of the star athletes who share the same Eton training facilities as him did so well in Sydney. Gold medal-winning heptathlete Denise Lewis, Australia's 400m champion Cathy Freeman, British sprinters Darren Campbell (who won a silver in the 200m), Dwain Chambers and Jason Gardener - all regulars at the track - performed brilliantly.

Richardson begrudged them nothing, but admitted: "It was tough and very lonely when the people from my training group were enjoying lifetime ambitions, and I was stuck here in the wind and rain, looking for a break in the clouds to train."

From his point of view, tonight's 400m is a "must-win" race.

Richardson said: "I don't expect to see Michael Johnson there, but whether he runs or not, I have something to prove against the other Olympic lads competing."

When he returns, Richardson will meet lawyers and his manager, Mike Whittingham, to prepare his defence against the alleged doping offence.

Richardson is relying heavily on research being done at an International Olympic Committee-accredited laboratory in Cologne which could prove the nandrolone allegedly found in his body was naturally, not synthetically, produced. The IAAF hearing is scheduled to be heard early next year. He said: "I believe wholeheartedly in catching drug cheats.

In the case of nandrolone, there is obviously a massive grey area. They are snaring innocents like me. With scientists so divided, this is ruining athletes' lives." But at least he is comforted by the support he is receiving from people both in and out of the sport.

Sebastian Coe has been in regular touch, urging him to "keep fighting" and another former Olympic champion, Daley Thompson, is also backing his case. Effingham Golf Club, in Surrey, made him their annual dinner guest last week, and schools continue to invite him to prize-givings.

Richardson added: "They know I haven't been cheating.

"I will be 32 when Athens comes around. Michael Johnson won his Sydney gold at 33. Anything is achievable once I clear my name."

Meanwhile, Olympic 100m champion Maurice Greene has turned down the chance to earn $500,000 (£357,000) by competing in Doha.

The American world-record holder has forfeited the chance of appearance money and a $200,000 prize for the athlete with the best grand prix record this season.