DENVER -- Swimming's international governing body hasn't quite decided whether to retest athletes' urine samples from the world championships for a new designer steroid.

World Anti-Doping Agency director general David Howman said Tuesday that FINA would retest samples from its world championships in July to search for THG.

But FINA said Wednesday that it is still studying the drug and trying to determine if the IOC/Wada Laboratory in Barcelona would be available for retesting.

"FINA continues to study with its experts the evolution of tetrahydrogestrinone (THG)," FINA said in a statement. "If the conclusion of the FINA experts will lead to the necessity of conducting tests for THG, FINA will proceed analyzing samples."

U.S. anti-doping officials discovered THG after an unnamed coach sent a syringe he says came from Bay Area Laboratory Co-Operative in California. Lab founder Victor Conte denies being the source.

Anti-doping officials have developed a screening process for the previously undetectable drug, leaving sports organizations scrambling to retest athletes.

Four U.S. track athletes tested positive for THG at the U.S. nationals in June, and Dwain Chambers, Europe's top sprinter, failed an out-of-competition drug test.

The NFL also is retesting its players' samples for the newly identified steroid.

The International Olympic Committee said it plans to add THG to its list of banned substances and test for it at the 2004 Athens Games.

THG testing is scheduled to take place at the Rugby World Cup next week and horse racing officials in Australia have added the steroid to its testing list.

International track officials also have decided to retest about 400 samples from the world championships in August.