Sebastian Coe has admitted that athletics cannot afford to lose the battle against doping following the scandal that has engulfed two of the world's top sprinters.
Positive tests by Tyson Gay, the fastest man in the world this year, and Jamaica's former world record holder Asafa Powell have sent shockwaves through athletics.
Coe, vice-president of the International Association of Athletics Federations and chairman of the British Olympic Association, said the fight against drugs in sport would continue.
Coe told Press Association Sport last night: "This is not a war we can afford to lose, and it is important for any athlete to know that if they want to risk cheating that they are going to get caught.
"Of course we would rather not wake up to the headlines that we have done today but we have taken a tough stance on doping and will continue to do so.
"We would rather have the short-term embarrassment from the sorts of stories we have today rather than a decline in the sport to a position where no one has any trust in the athletes. That's what we are fighting for."
It is not known which substance Gay has tested positive for - that should be confirmed after the result of analysis of his B sample.
Powell, who has run 9.88sec this year but failed to make the Jamaican team for next month's World Championships, was tested at the national trials in June and returned an adverse finding for oxilofrine (methylsynephrine), a stimulant that boosts fat-burning.
Jamaica's Sherone Simpson, a three-time Olympic medallist, has also tested positive for the same substance.
The news has prompted sportswear giant adidas to suspend its contract with Gay, after it invoked a clause in its contract dealing with doping.
The company said in a statement: "We are shocked by these recent allegations, and even if we presume his innocence until proven otherwise, our contract with Tyson is currently suspended.
"adidas has a clear policy on doping and drug use - each of the agreements with our athletes include a clear clause which states that the agreement shall be terminated by adidas if the athlete is found guilty of the possession or use of drugs or any other prohibited substance by the relevant governing sports body having jurisdiction over the athlete."
The hotel in Italy where Powell and Simpson are staying has been raised by police who confiscated some substances for analysis, according to media reports.
The raid took place early yesterday at the hotel in Lignano Sabbiadoro in northern Italy and was requested by the athletes themselves, according to their manager.
"Asafa and Sherone have been working with Wada to arrange this police raid, so to speak," Paul Doyle told the Daily Telegraph.