The World Anti-Doping Agency said on Sunday it will distribute more user-friendly guidelines for drug-testing under its whereabouts rule but stressed there would be no easing of the controversial policy.

The whereabouts rule, which requires athletes to give three months’ notice of where they will be for an hour each day, has become a major source of tension between the doping agency and international sports federations, including soccer’s world governing body FIFA.

“The rules aren’t going to change, there is no suggestion that there is a need to change those rules,” WADA president John Fahey told reporters after weekend meetings with the agency’s executive committee and foundation board. “Maybe we could have been better with our guidelines … There has been some evidence of some strange interpretations.”

WADA promised a review of the rule after one year and found it to be an important weapon in the fight against doping.

But the anti-doping agency also admitted it could have done a better job explaining the rule and said a motion was endorsed this weekend to circulate more user-friendly guidelines as soon as possible.

“A review was undertaken, that review was reported back to us this weekend and again it showed there was a successful implementation of the program,” said Fahey. “But there were different interpretations by different sports, different countries that clearer guidelines might assist.”

A report delivered by the international police agency Interpol also provided WADA with a sobering wake-up call.

While WADA has focused on testing and catching drug cheats, Interpol warned the front line in the war had shifted to supply and trafficking of performance enhancing drugs.

According to Fahey, evidence from Interpol suggests there is almost as much money, if not more, coming out of performance enhancing drugs as there is in the illegal drug trade.

“There is a problem of mammoth proportions out there,” warned Fahey. “If we were of the view that the problem was going away that was not the advice we were given by Interpol.

“I don’t think it was shocking but sometimes when we’re all working as hard as we can on the particular issue of getting rid of the cheats in sport you don’t stop to take stock what the proportions of the problem are.”

(Editing by Frank Pingue; To query or comment on this story email sportsfeedback@thomsonreuters.com)