Poland's police say they have arrested 14 people and seized 100,000 fake Viagra pills and 430,000 portions of fake doping substances worth millions of euros in a raid on an illegal factory.

The Police Central Bureau of Investigation said earlier this week it raided the factory in apartment house near Bydgoszcz, in central Poland, and a number of other sites, run by a group that produced and distributed the substances.

They said Thursday it was the biggest illegal factory of fake medication they have seen. They seized substances valued at over 4 million euros ($4.5 million), and some 1 million euros worth of production machines.

Components were brought chiefly from China and the products were offered on the internet.