Why don't ask your upper neighbours a copy of their papers?
http://www.necedo.nl/nzvtThe supplements have been tested a long time ago after two dutch football(soccer)players had been suspended after alleged using doping. After a conducted investigation the conclusion was that the main source was a polluted supplement. They now have a list with suppliers with clean products and they're been tested regularly. .
Yet it doesn't justify the question how this stuff get in these supplement. Cause you can do a lot in the Netherlands, but it ain't Sodom and Gomorrah. Not everything is legal.