The Medicines Board says it is concerned about an increase in the number of emails and websites offering drugs to treat the Influenza A9(H1N1) virus.
The IMB says people should not buy medication online under any circumstances, as there is no way of ensuring its safety, quality or effectiveness.
Interpol estimates that between 3 and 4% of all spam emails being circulated at the moment relate to the influenza A outbreak and says hundreds of new web pages on the subject have been established.
In a statement this evening, the Medicines Board says anti-viral treatments for influenza A(H1N1), also known as swine flu, should only be prescribed by doctors.
The board's Chief Executive, Pat O'Mahony, says there is a real danger that if people take substandard medicines as a preventative measure, they could build up a resistance to genuine treatments which they may require in future.
He has urged consumers not to buy any medicines online, and to instead contact their GP if they have any concerns about their health.
