Despite several high-profile withdrawals in the past week 32 Olympic [Images] champions will take part in the 10th world championships opening in Helsinki on Saturday.

After 22 years the event has returned to Finland, which staged the inaugural championships at a time when successive boycotts had threatened the future of the Olympic Games.

"It is often said that the soul of track and field athletics resides in Finland," said International Association of Athletics Federations president Lamine Diack.

"There is no other place in the world where the public love athletics with such deeply held passion and understanding of the technicalities of the event."

In a grim reminder of the sordid realities of modern professional sport, however, Diack also said that virtually one out of every two athletes would undergo a drugs test during the championships.

"We plan to have the most ambitious and comprehensive system of testing ever activated at a world championships," he said.

As part of the never-ending battle to combat the drugs cheats, 100 blood tests will be carried out and there will also be tests for human growth hormone.

The first weekend features the men's 100 metres, with American Olympic champion Justin Gatlin the favourite after the new world record holder Asafa Powell [Images] pulled out through injury.

CAMPBELL DOUBLE

In his absence, Jamaica's best hopes of a gold medal rest with Olympic 200 metres champion Veronica Campbell who is attempting the double in Helsinki.

"I would say both are very challenging but the 100 metres is a bit different, it's the most technical," said Campbell, who won the bronze medal at last year's Athens Games.

"I think the 100 is up for grabs. It's going to come down to whoever needs it the most and whoever gets that blast and powers through the line. It should be very exciting."

Saturday also features the start of the heptathlon when Sweden's Carolina Kluft settles in the blocks for the 100 metres hurdles.

At the age of 22, Kluft has won every available title and her challenge at the weekend will be to overcome the challenge of France's [Images] 1999 world champion Eunice Barber.

Kluft became the third woman to amass more than 7,000 points at the Paris world championships two years ago and Barber is keen to join her.

"I'm ready to score 7,000 points," said Barber. "I am back, I have found the competitive spirit again."

Kluft is confident of improving on her Paris total of 7,001.

"I feel really good," she said. "I think I will be able to beat my own personal best."

While Kluft is already the world and Olympic champion, Britain's Paula Radcliffe is still seeking a medal of any colour at a global championships.

The world marathon record holder failed to finish either the marathon or the 10,000 metres in Athens during a traumatic week.

She recovered to win the New York and London [Images] marathons and has decided to attempt both races again in Finland.

Radcliffe has made it clear, however, that her primary focus is on the marathon on Sunday week rather than Saturday's 10,000.

"I have never said I am doubling up," she said. "My focus on the marathon."

Two other finals will be decided on Saturday, the men's 20 kilometre walk and the men's shot put.

The latter event features veteran American John Godina, who attempts his fourth world title after struggling with a daunting list of afflictions.

Godina, 33, has sustained an injury to his foot plus injuries to both elbows.