The British Olympic Association (BOA) has been urged to scrap its policy of issuing lifetime bans to drugs cheats.
Travis Tygart, chief executive of the United States Anti-Doping Agency (Usada), said it was contrary to globally agreed procedures.
The BOA's strict stance goes far beyond the sanctions demanded by the World Anti-Doping Agency (Wada).
"Once you set the rules and the world agrees to them, you ought to play by those rules," Tygart said.
"Let's not go outside (the Wada) process, like the BOA has, and have a rule that supersedes the rules we've all signed up to as the final word on what the sanctions should be.
"If we want lifetime bans - and that could be the right thing to do to protect clean athletes - let's do it via Wada so that it applies to every country.
"Let's have that discussion about increased sanctions but you cannot have one country doing it when everybody else doesn't."
Tygart's comments come three days before a Court of Arbitration for Sport (Cas) ruling in Switzerland is expected to seriously weaken the legal status of the BOA's cherished by-law 25.
The Wada Code, which came into force in 2004, harmonised rules around the globe and brought in a maximum ban of two years for athletes who test positive for performance-enhancing drugs.
But in 2008, just before the Beijing Olympics, the International Olympic Committee (IOC) brought in its own "increased sanction" of an automatic ban from the next Games for anybody given a suspension of longer than six months.
By far the most high-profile "victim" of the IOC's rule 45 is LaShawn Merritt.
The American 400m star inadvertently failed a drugs test for a substance contained in a male-enhancement product and was given a 21-month suspension by the American authorities. Under the new IOC regulation, this also ruled him out of the chance to defend his Olympic title at London 2012.
But Merritt and his supporters said this amounted to a three-year ban and his case was taken up by the United States Olympic Committee. Their appeal has gone to Cas, sport's highest court, with most observers predicting an IOC defeat.
Merritt's initial suspension expired this summer and he returned to competition at the 2011 World Championships, where he won an individual silver medal and relay gold.
But it is the implications of the Cas ruling on the BOA by-law that is dominating debate here, with the controversy surrounding Dwain Chambers' attempt to gain selection for the Beijing Olympics still fresh in the memory.
Introduced in 1992 to tackle a threat that was perceived to be growing, the by-law has often been at the centre of legal argument, usually when athletes have used the appeals process to keep their Olympic eligibility, none more so than when Christine Ohuruogu successfully appealed in 2007.
But the hardline stance on drugs cheats has proved to be popular with the public and the vast majority of British Olympians.
The BOA is also confident its rulebook is in accordance with the Wada Code and has received written assurances to confirm this from the Montreal-based body as recently as March 2009.
Tygart acknowledged the BOA by-law was a better piece of legislation than the IOC rule, as it allowed for "individualised review", but said it still undermined Wada and should be dropped. This would mean reprieves for the likes of Chambers and banned cyclist David Millar.
The Usada boss was speaking at the Laureus Science and Ethics in Sport Symposium in London where there was significant support for the BOA's position.
Colin Jackson, the double world 110m hurdles champion and Olympic silver medallist, urged Britain's national Olympic committee to "stick to its guns".
"You are an ambassador for your country when you compete at an Olympics," said Jackson.
"If we decide we don't want anybody who has taken drugs to be our ambassador then so be it. I have very little room for movement on the subject of drug-taking."