The US Food and Drug Administration (FDA) has accused a British online pharmaceutical supplier of allegedly selling illegal drugs to the American public in wake of the recent bio-terrorist attacks on the US. Harrow-based Internet company MastersMarketing.com was one of 11 foreign pharmaceutical companies to receive an email from the FDA last week. The letter warned the suspect vendors against marketing illicit batches of ciprofloxacin -- an antibiotic used to treat anthrax -- and is threatening to take action against suppliers who continue to sell their products to US citizens. The FDA said in a statement that is taking these steps to "protect the American public against the potentially useless or harmful drugs to treat anthrax infection that are being marketed by foreign Web sites in defiance of United States laws." The warning highlights the lack of regulation controlling the sale of illicit products on the Internet. E-commerce companies are governed by the laws of the country in which their servers are based, making it difficult for a country to take legal action against a Web site that falls out of its jurisdiction. MastersMarketing.com claims to have halted the sale of ciprofloxacin after receiving the FDA letter, and insists that it all of its drugs are supplied by internationally recognised manufacturers. "Many members of the general public in the US will be upset by this action from the FDA. The cost of these drugs inside the US is prohibitive for many people," said Ashok Kumar of MastersMarketing.com. "Sites like ours give the public access to legal, affordable drugs. Surely members of the public should have the right to buy products for their own health from overseas?" Ciprofloxacin is a powerful antibiotic that has been associated with serious side effects, and so should only be available on prescription. But the growing threat of biological warfare has prompted American citizens to look online for drugs that claim to prevent exposure to anthrax. The FDA is concerned that some of these products are counterfeit, and not made in accordance with US specifications. "Foreign manufactured ciprofloxacin has not been approved or evaluated by FDA, and the manufacturing practices for production of these drug products has not been regulated by the agency to assure the drug's safety, identity, strength, quality or purity," reads the FDA statement. Federal law makes it illegal for individuals to import drugs that are not approved in the US, including foreign versions of US-approved drugs. The FDA will be informing relevant regulatory officials that potential violations are taking place, and is advising the US Customs Service to block ciprofloxacin shipments to America. See the E-commerce News Section for the latest headlines. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the ZDNet news forum. Let the editors know what you think in the Mailroom. And read other letters.