Health officials in the U.S. have expressed concern that with the current panic in many countries regarding bird flu, a counterfeit industry to produce the drug Tamiflu may already be in existence.
It is believed at present that Tamiflu is one of the few drugs that can treat the feared avian influenza.
U.S. Food and Drug Administration Director Dr. Andrew von Eschenbach has therefore set up a "rapid response team" to make sure enough of the legitimate drug will be manufactured in the case of a pandemic of H5N1 avian flu.
Officials are apparently confident that there will be enough of the antiviral medication to treat Americans in the annual epidemic of seasonal flu, which kills an average of 36,000 people in the United States alone every year.
However Health and Human Services Secretary Michael Leavitt says there is some concern that there may be a threat of counterfeiting with respect to Tamiflu.
The H5N1 strain of avian influenza which is affecting flocks of poultry in many parts of Asia and some parts of eastern Europe, has killed more than 60 people so far in four countries and millions of birds have been destroyed.
As yet it does not easily infect humans, but experts fear it will acquire this ability and cause a pandemic.
The virus while it appears resistant to one of four available influenza drugs, amantadine, two other drugs, Roche's Tamiflu, and GlaxoSmithKline's Relenza, work against the virus, and there is evidence that another older influenza drug called rimantadine may also work.
Media headlines about Tamiflu have of course encouraged the panic, and countries are now scrambling to stockpile the drug which is great news for drug company Roche who cannot make the drug fast enough to meet all the demand.
The company says it will talk to other companies about licensing it to meet demand.