Police in several European countries on Monday arrested 12 people and seized millions of euros in assets in a swoop on counterfeit Viagra dealers, authorities said.
The operation against fake, prescription-only medicines, "mainly erectile dysfunction pills", involved police in Austria, Belgium, Cyprus, Hungary and Britain, European justice organisation Eurojust said in a statement.
"Operations resulted in the seizure of several million pills with an estimated value well in excess of 10 million euros ($13.1 million), a large amount of cash and several vehicles, including luxury models, and the freezing of more than 7.5 million euros in bank accounts and assets," Eurojust said.
The counterfeit drugs were imported into the European Union from China and India and "often contain incorrect dosages and ingredients".
According to the European Alliance for Access to Safe Medicines, 62 percent of drugs bought on the Internet in 2011 were fake.
The Center for Medicine in the Public Interest, a US non-profit medical research group, estimates the traffic in fake medicine generated 55 billion euros globally in 2010, up 90 percent from 2005.
A study conducted by pharmaceutical giant Pfizer in 2010 showed that the European market for fake drugs was worth around 10.5 billion euros.