Athletics/US Olympic trials:  Historically a meeting with the sparkle and tension of the Olympic Games, the US trials starting today are a test not only of America's best but of the sport itself.

In a setting less than three hours' drive from the Bay Area Laboratory Co-Operative (BALCO), alleged to be at the heart of a doping scandal which threatens to engulf the sport, the United States will pick its team for the Athens Olympics.

It is here that triple Olympic champion Marion Jones, returning after giving birth to her first child last year, will attempt to shake off a spring and early summer of disappointment and again make the team in the 100 and 200 metres and long jump.

It is here that Olympic champion Maurice Greene will attempt to show he is still the king of the 100 metres. Veteran hurdlers Gail Devers and Allen Johnson will take their first steps towards more gold while emerging 1,500 metres runner Alan Webb and shot putter Christain Cantwell will bid to make their first Olympic team.

Yet, reminders of the BALCO scandal will not be far away. Six athletes, including Jones's partner and 100 metres world record holder Tim Montgomery, will compete although awaiting hearings on doping charges.

Four others, including world double sprint champion Kelli White, have been suspended for doping violations.

Even the sport's biggest female name, Jones, is under scrutiny by the US Anti-Doping Agency (USADA) although she has never failed a doping test and has denied using performance-enhancing drugs.

"We've had trying times as an organisation over the past 25 years," USA Track & Field chief executive Craig Masback told his board of directors this week. "But nothing is more challenging or dispiriting then the situation in which we find ourselves. Instead of a daily celebration of our great sport and our outstanding athletes, newspapers around the world are delivering news of scandal and shame related to some of our athletes and coaches."

Masback blamed the scandal on "a small sub-culture of cheating athletes and coaches" whom he said believe "that using performance-enhancing substances was an acceptable route to success".

The top three finishers in each event will comprise the team for Athens, if they have met the Olympics qualifying standard.