-- Just one scientist or scientific group likely masterminded the creation of the two barely known steroids at the center of the Bay Area Laboratory Co-Operative (BALCO) scandal, the lab director who identified the two drugs said Wednesday.

"The more I think about this and put it all together, I become more and more convinced that whoever was behind this knew quite well what they were doing," said Don Catlin of the UCLA Olympic Analytical Laboratory in Los Angeles. "This was sophisticated work. . . . I don't know whether it was one person alone or a consortium . . . [but] I see no reason to suspect there are two independent groups" who made the steroids.

Catlin's remarks came via telephone during a session with reporters at U.S. Anti-Doping Agency headquarters after bans were handed out to five athletes -- Regina Jacobs, Kevin Toth, John McEwen, Melissa Price and Dwain Chambers -- who last summer tested positive for THG, one of the two steroids Catlin identified.

In its February indictment of four men connected to BALCO on federal steroid distribution charges, the government alleged that the two steroids, norbolethone and THG, were provided to athletes under the code name "clear." The government did not speculate on the source of the drugs, which had previously been undetectable in standard urine screens.

In May, the San Jose Mercury News reported that Victor Conte, the owner of BALCO, told federal investigators that famed supplement-maker Patrick Arnold supplied THG, whose chemical name is tetrahydragestrinone and which Catlin identified last summer. Two years ago in an interview with The Post, Arnold, who created the recently banned over-the-counter steroid andro, denied a connection to any athletes but said he might at one time have made norbolethone, discovered by Catlin in 2002.

After Catlin unearthed the drugs, one cyclist tested positive for norbolethone and five track and field athletes tested positive for THG. All received bans of varying lengths from their sports' governing bodies. It is unclear, however, how widespread the use of the drugs was before officials had the means to detect them. Catlin speculated that norbolethone was used as far back as 2000.

Federal officials have not charged anyone in connection with the production of the drugs, which are not technically illegal since they are not among the anabolic steroids specifically banned by Congress in 1990.

Catlin speculated that a knowledgeable scientist manufactured norbolethone after reading about its properties in old steroid literature. Wyeth Laboratories in Philadelphia studied norbolethone during the 1960s but it eventually abandoned the research and never marketed the drug. Catlin said he believed the producer obtained gestrinone -- a banned anabolic steroid that can be purchased online from overseas sources -- and bubbled hydrogen gas through it to create norbolethone and then, by shortening the process, THG.

"People out there somewhere were bound and determined to make steroids we wouldn't know about," said Catlin. "The story is not over."

In other news, USADA officials revealed that they received three telephone calls from the anonymous coach who on June 5, 2003, mailed them a syringe that contained THG and led to its discovery. USADA spokesman Rich Wanninger said the coach provided several pieces of information:

* The coach claimed that four U.S. athletes and one international athlete were receiving an undetectable steroid similar to Genabol -- another name for norbolethone -- from Conte and had no fear of testing positive. The coach also said track coach Remi Korchemny was involved. Korchemny was among the four men, including Conte, indicted in February. All have pled not guilty.

* The coach claimed the drug was sometimes mixed with flaxseed oil and ingested by placing a few drops on the tongue.

* The coach also claimed that Conte showed up to the U.S. track and field championships in June 2003 and distributed substances to athletes from a black bag.

The Mercury News reported in July that Trevor Graham, the former coach of Marion Jones, provided the syringe to USADA. Graham has repeatedly declined to comment. His name, meantime, has surfaced in connection with other drug charges. Sprinter Tim Montgomery told the BALCO grand jury that Graham himself was involved in the distribution of banned drugs, according to the San Francisco Chronicle.

Graham's attorney has stated that his client has no connection to such activities. Graham has coached three of the four athletes -- Montgomery, Michelle Collins and Alvin Harrison -- facing lifetime bans from USADA for alleged drug violations connected to BALCO.

USADA CEO Terry Madden said Wednesday the agency might pursue action against coaches or others believed to have assisted in giving banned drugs to athletes, but offered no timetable.

"We may be proceeding in more directions after all the BALCO information comes out," he said. "It might not just be athletes. We have a duty, in fact, to pursue coaches that may have been involved."

USADA officials also on Wednesday described a previously unknown level of cooperation between anti-doping officials and federal investigators, as well as between USADA officials and international sport officials, citing a number of secret meetings throughout last summer as THG was being identified.

Catlin said Jeff Novitsky, the lead investigator in the BALCO case, contacted him in the fall of 2002 for assistance in identifying drugs discovered in connection with a lab in Northern California.

In August of last year, USADA officials alerted the Department of Justice about THG and their suspicions about Conte and BALCO. Days later, on Aug. 11, 2003, Madden said, government officials informed USADA that its investigation and the government's in Northern California centered on the same lab: BALCO.

On Aug. 19, Novitsky and a San Mateo narcotics official flew to Colorado Springs to interview USADA officials, Madden said. After that, the agency developed a relationship with Jeff Nedrow, the assistant U.S. attorney in the Northern District of California assigned to the case, Madden said.

USADA officials also alerted the world governing body of track and field (IAAF) to the existence of THG in July of last summer, requesting increased out-of-competition testing before the world championships and targeted testing on nine international athletes it suspected of possible involvement.

"I've never seen such a good, coordinated effort among so many people," Bowers said.