I did a bit research after I purchased counterfeit USPS stamps. I found this company that makes security stamps, tax stamps, cigarette tax stamps, and postage stamps. They make postage stamps for many countries include UK, US, Australia, Netherlands, etc. Stamp collectors or postage buyers, you can assume the whole of the secondary market is flooded with counterfeits, since there is no way legitimate stamps can compete with their production price. And they are getting better. On their website they claim their new stamp is tagged and can pass UV test.
People and distributors then buy it from this company on Alibaba and sell for a fraction of the face value on eBay. This need to be exposed. I have contacted federal authorities but they are slow. If more people bring it to their attention they might take them down faster. There could be rewards if your lead is worth something.
