World athletics boss Lamine Diack opened the meeting which will choose his successor on Wednesday with a defiant stab at track and field's doping detractors, saying they had painted the sport as a "monster".

Diack, 82, is stepping down as president of the International Association of Athletics Federations (IAAF) after 16 years in charge, with Sergey Bubka and Sebastian Coe later facing off in a vote of the 214 member federations to take over.

IAAF has been mired in recent weeks over allegations of widespread doping in the sport, but Diack was in defiant form as he took to the dais for one last time in his current role.

"We have the world championships here in Beijing and people will say 80 percent of the athletes are bound to test positive. That's absolutely not true," he said.

"All champions need to be tested regularly," he said, citing the establishment of the US Anti-Doping Agency (USADA) which cut down on the number of positive tests that came to light in the United States in the 1990s.

"If all countries followed that example, in Kenya, Morocco, Ethiopia and Turkey, and elsewhere, it will enable us to resolve this problem."

Diack added: "We spend millions of dollars every year to ensure athletes are protected and remain clean.

"For weeks, people are talking about doping in athletics, the sport has turned into a monster in the eyes of newspapers, saying everyone is doped.

"Opinions are swayed in this way."

Diack said it was important to remember that "everything done in terms of anti-doping in sport comes from athletics".

"The incoming team will continue this work... and I hope they can go even further than me and my team," the Senegalese said.

"We have to introduce new measures and improve," Diack said, calling IAAF's anti-doping work "unparalleled".

The credibility of both athletics and the IAAF has come under repeated attack in recent weeks, after British and German media said a leaked database of 12,000 tests had revealed "extraordinary" levels of doping.

The IAAF slammed the allegations as "sensationalist and confusing" and also dismissed a later Sunday Times report that it blocked the publication of a document showing extensive doping among top athletes.

Last week, the world body provisionally suspended 28 athletes for suspected doping offences at the 2005 and 2007 world championships, although most have now retired and none had been due to compete at the world championships in Beijing, starting Saturday.

But doping issues will feature prominently at the Bird's Nest stadium when US sprinter Justin Gatlin, twice banned for drugs but now in the form of his life aged 33, takes on Jamaican superstar Usain Bolt in the 100m on the opening weekend.