Dwain Chambers is not on the guest list but his shadow fell over one of the most glittering sports ceremonies of the year yesterday. The Laureus Sports Awards attract the biggest names, with legends such as Boris Becker, Ilie Nastase and Franz Beckenbauer, rubbing shoulders with bright new talent such as Lewis Hamilton. This city's soaring architecture and the frozen tributaries of the Neva River that criss-cross it, announced centuries of history to the celebrities arriving for this evening's awards. But the tensions of modern sport bubbled to the surface as the nominations were announced with one of the greatest athletes of all time wading into the controversy that has surrounded Chambers's attempt at a comeback.

Ed Moses, of the United States, an Olympic gold medal-winner at 400 metres hurdles in 1976 and 1984 who set a world record in his event on four occasions, has, during his retirement, worked with the International Olympic Committee to combat the use of drugs in sport.

Now one of the chairmen of the Laureus Foundation, which helps thousands of underprivileged children around the world through sport, he would not condemn Chambers's return to the track, an issue which has consumed UK Athletics.

As far as the American is concerned, Chambers has served his time, which was a maximum sentence laid down by the IAAF, the world governing body for athletics.

“Sporting organisations are going for two-year bans and if an athlete serves two years then they are able to compete. That's it,” he said. But Moses argues that the punishment does not yet fit the crime and said that the authorities need to double the two-year sentence to make it an effective deterrent to potential drugs cheats.

A four-year ban could wreck the careers of offenders because the term would almost certainly mean that athletes would miss at least one Olympic Games plus two World Championships. Moses stepped back from arguing for a life ban because the four-year cycle would effectively do that job, cancelling out the best competitive years in the lives of banned athletes.

“I personally would look for a four-year ban,” Moses said. “An athlete may need to miss an Olympic cycle to appreciate the scale of the penalty. Nobody keeps training for four years, nobody hangs around that long. It is the equivalent of a life ban.”

But the list of nominees for the awards has stoked another, more minor, controversy. In the Comeback of the Year category, Christine Ohuruogu is, ironically, pitted against Paula Radcliffe, one of the most outspoken critics of drugs cheats in her sport.

Ohuruogu is expected to win the trophy, which will leave the way open for critics to point out that her comeback to win the 400 metres at the World Championships came after serving a one-year ban for missing three out-of-competition drugs tests in a case that caused almost as much heart-searching as Chambers's return: Radcliffe came back to win the New York Marathon after having a baby.

Laureus organisers will hope that the Ohuruogu issue does not cloud an event that celebrates sport and attempts to reach out to those youngsters whose lives can be improved by the huge sums of money raised by some of the world's greatest athletes.

But after the last celebrity leaves St Petersburg, the Chambers saga will go on. Nick Collins, his lawyer, has to decide whether to mount a High Court challenge to the British Olympic Association (BOA) bylaw that automatically bans convicted dopers from the Olympics for life. Some legal experts have questioned the validity of the bylaw, which is unique in world sport, but it will come down to money. In 2006, Chambers was ordered to pay back £120,000 in prize-money and earnings to the IAAF. He has revealed that anything he earns will be used to pay off his debts, so the prospect of losing a legal fight that could cost him £200,000 would be disastrous.

Lord Coe, chairman of the London 2012 Olympics committee, aligned himself with Moses yesterday by reiterating his desire to see the punishment for a first doping offence increased from two to four years. He added that athletics was in danger of becoming a farce. “We could end up with a situation like WWE wrestling, where everyone knows it is fake and they don't care,” he said.

Allan Wells, the 1980 Olympic 100metres champion, said that he would no longer work with the BOA if Chambers is allowed to run in Beijing.