A dietary supplement marketed to fitness and health enthusiasts on the Internet and in body-building shops contains anabolic steroids linked to two of the biggest doping scandals in sports history, including the renowned case involving East German Olympic athletes in the 1960s and '70s, according to a prominent researcher.

The supplement, which is sold under the name Halodrol-50, contains a steroid that closely resembles Oral-Turinabol, the principal steroid used to fuel East Germany's secret, systematic sports doping program, according to Don Catlin of the UCLA Olympic Analytical Laboratory.

Catlin said it also contains DMT, or madol, a steroid federal authorities say was developed for Bay Area Laboratory Co-operative (BALCO), the California nutritional supplement company at the center of a scheme to provide prominent professional athletes with undetectable performance-enhancing drugs.

Catlin analyzed the makeup of Halodrol-50 for The Washington Post, which purchased the product on the Internet and reimbursed the Los Angeles researcher for the cost of the testing.

The discovery provides further evidence that the country's multimillion-dollar dietary supplements industry also has become a clearinghouse for the distribution of anabolic steroids, which help build muscle and speed recovery from strenuous exercise but also can cause serious health problems when used in excess.

Last month, Catlin tested five other dietary supplements obtained by The Post and found that each contained anabolic steroids, four of which had not been previously detected. The Food and Drug Administration announced after publication of The Post's story on Oct. 18 that it had opened an investigation into the four companies marketing them.

An FDA spokeswoman said yesterday that the investigation is continuing. The official declined further comment.

It is illegal to sell anabolic steroids or any unapproved drugs as dietary supplements.

Halodrol-50, which costs $50 to $80 for a bottle of 30 tablets, is marketed by Gaspari Nutrition, a dietary supplements company based in Neptune, N.J., that sells bodybuilding and weight-loss products. Halodrol-50 claims on its label to "induce maximal visible changes in size and strength in the shortest period of time possible." It also recommends that the product not be used by anyone under age 21.

The Halodrol-50 label further states that it contains polydehydrogenated, polyhydroxylated halomethetioallocholane. Catlin described that chemical descriptor as "hocus-pocus." He said the language was outdated and vague and appeared to be deliberately misleading. The label makes no mention of DMT or other anabolic steroids.

"It's obfuscation," Catlin said. "There is no attempt to be clear and concise and to describe the product for what it is."

Rich Gaspari, owner of Gaspari Nutrition, did not respond to two requests for an interview made by telephone to associates at his company. He also did not respond to two e-mail requests for comment.

However, Bruce Kneller, a consultant to Gaspari, wrote in an e-mail late yesterday that he had spoken to Gaspari and was conveying a comment on Gaspari's behalf. "The product . . . was discontinued several weeks ago after the publication of an inflammatory article in The Washington Post," Kneller said, referring to the Oct. 18 Post story. "It is no longer made or sold by Gaspari Nutrition and, in fact, was only available for less than three weeks."

Though Halodrol-50 is no longer available on the Gaspari Nutrition Web site, the product continues to be marketed on other Web sites that sell bodybuilding substances.

In an e-mail sent by a Gaspari official to a distributor, which was provided to The Post, the Gaspari official said Halodrol-50 and another product called Orastan E no longer advertised on Gaspari's Web site would continue to be sold to good customers. The Gaspari official added that he hoped "the government and media will ignore us and think we got rid of them," focusing instead on the "other companies."

Oral-Turinabol anchored the secretive doping program in communist East Germany that led to that country's emergence as an Olympic power three decades ago, according to classified documents uncovered in 1990 following the fall of the Berlin Wall. At the 1976 Summer Games in Montreal, East German women won 11 of the 13 swimming events. But the side effects from the massive doses of steroids administered to the East German competitors were as remarkable as the athletes' successes. Women developed excessive body hair, deepened voices, massive shoulders and male secondary sex characteristics.

Criminal trials in 2000 resulted in the convictions of East Germany's Olympic president and chief sports doctor, but a number of former athletes are still grappling with medical, legal and psychological issues related to the doping program.

One of the two steroids found in Halodrol-50, Catlin said, more closely resembles Oral-Turinabol than any other known steroid, but the two are not identical in structure. The steroid would be undetectable in standard drug tests because it is not an exact match with Oral-Turinabol.

"This is an unknown," Catlin said. "If I had to pick one it's ever so close to, it's Oral-Turinabol. . . . It's very close."

Athletes taking Halodrol-50 would flunk standard sport drug tests, however, because DMT -- which Catlin identified more than a year ago -- is now detectable. DMT was one of three steroids found associated with BALCO. The others were norbolethone and THG, also known as "the clear."

The FDA is investigating four other dietary supplement companies named in the Oct. 18 story in which The Post reported that Catlin had found anabolic steroids in five products produced by four companies: Anabolic Xtreme, Applied Lifescience Research Industries, Legal Gear and PharmaGenX. The story led Rep. Thomas M. Davis III (R-Va.) to demand that the FDA explain its efforts to ensure that dietary supplements did not contain steroids. The FDA said in a Nov. 7 letter to Davis that the companies could face punitive action.