Outgoing athletics chief Lamine Diack admits his sport is in crisis because of the doping allegations leveled at it over the last month but still believes "99 percent" of athletes are clean.
The International Association of Athletics Federations (IAAF) has endured three torrid weeks of embarrassing leaks and accusations that it has neglected its duty to root out drug cheats.
Diack's 16 years as IAAF president will come to an end when he is replaced by President-elect Sebastian Coe at the end of the August 22-30 world championships, but the Senegalese has no intention of going meekly into retirement.
"We found ourselves in a situation where there were serious accusations, allegations of doping, about the very ethics and integrity of our sport," he said at the closing press conference of the 50th IAAF Congress.
"Of course there is a crisis, because we are targeted by these accusations. What was the aim of these accusations I cannot tell you," Diack said. "We can't afford to have our performances in doubt. We are convinced 99 percent of our athletes are clean."
The accusations, based on leaked test data obtained by two media organisations, are that the IAAF have allowed athletes to continue to compete despite submitting suspect blood samples.
Diack repeated his assertion from the opening session of the Congress that athletics had been in the vanguard of fighting doping and had nothing to learn from any other sport.
"I do 3,000 tests per year and I have 200 tests positive and 2,800 that are negative. You focus on the news, that is the 200 positive tests," he said.
"We have no lesson to be taught by any other sport. We have done what we had to do before the others against this standing struggle," Diack said. "We will continue to do our job like we have always done."
He said he was confident that his successor Coe, who has already announced that he will set up an independent anti-doping agency for athletics, would be equal to the task of defending the sport against its critics.
"We have a new president-elect and at this time when I leave I say I leave behind a sport that is marvellous with beautiful performances," Diack said.
"Seb is big enough and strong enough to face up to these allegations and to show that wrong accusations are indeed wrong accusations," he added. "He loves this sport and he is very experienced. He will do his job he will do a great job. He knows much more about sport than I do."