HERNDON, Va. - For years, human growth hormone has been considered one of the main banned substances used by athletes who want to build strength and avoid getting caught.

Now a company in Virginia says researchers who originally set out to work on diagnosis and treatment of cancer have developed a test that can find HGH in urine, something one anti-doping expert believes “could be a quantum leap forward” in the fight against drug use in sports.

Scientists from Italy and George Mason University have developed particles that can trap microscopic elements in fluid, and a company called Ceres Nanosciences owns the patent for the technology.

“No one’s ever been able to see HGH in urine at all, let alone collect it and analyze it,” Ceres Nanosciences CEO Thomas Dunlap said Friday.

Dunlap acknowledged the tests couldn’t be used until after trials and baseline testing that could take six months or more, but added: “The fact that we can see HGH at all is an enormous step. It’s the hurdle that everyone in the industry has faced.”

News of the urine test was first reported by the Washington Business Journal.

Naturally produced in the pituitary gland, HGH stimulates liver and other tissues to secrete chemicals that stimulate growth. It is prescribed for children with growth issues and adults with pituitary gland problems.

Synthetic HGH is hard to detect and is believed to work well in combination with other banned substances.

At a congressional hearing in February, commissioners and union chiefs of the NFL, NBA, NHL and Major League Baseball told lawmakers they were hoping for a dependable way to detect HGH through a urine test. They would prefer that to a blood test, which is more invasive and which can only detect HGH use over a 24- to 48-hour period.

Dunlap said he thinks he is on the way to being able to provide a test that could detect HGH longer after its use and has been in touch with the World Anti-Doping Agency. If and when the new test is approved, he hopes sales of that product will fund future research into applying the nanoparticle technology to cancer.

“The company is certainly legitimate. This is not a hoax. Their strategy, their idea, is a great one — if it works,” anti-doping expert Don Catlin said in a telephone interview from California. “If it really does work, it’s quite remarkable. It’s phenomenal.”

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Catlin oversaw testing for anabolic agents at the 1996 Atlanta Olympics and ran the country’s first anti-doping lab at UCLA for 25 years. He now runs Anti-Doping Research, a nonprofit organization he founded to research performance-enhancing drugs, uncover new drugs being used illegally and develop tests to detect them.

Catlin has been studying HGH for a decade. In 2006, Major League Baseball gave him $500,000 toward the development of a screen for the substance.

“Hundreds of people and millions of dollars in research have been involved in trying to find HGH in urine, and no one has been able to do it,” Catlin said. “This particular method has the potential — I’m not saying it does it, but the potential — to be a big step. It’s delightful. It could be a quantum leap forward.”

International Olympic Committee spokeswoman Emmanuelle Moreau said she wasn’t aware of the new urine test for HGH, but added that the IOC would welcome advances in anti-doping detection, provided they are authorized and peer-reviewed.

“Should there be a serious improvement, we will study that carefully,” Moreau said.