Users of the drug crystal methamphetamine may be causing euro banknotes to disintegrate, German police have told Der Spiegel magazine.
Banknotes crumble shortly after withdrawal from cash machines
Sulphates used in the production of the drug could form sulphuric acid when mixed with human sweat, they say, causing banknotes to corrode.
Drug users sniff powdered crystals through rolled up banknotes.
About 1,500 banknotes have crumbled after being withdrawn from cash machines, German banking officials say.
Much of Germany's supply of crystal methamphetamine is believed to come from eastern Europe, and has a high concentration of sulphates.
Its corrosive effects are also spread between contaminated notes and clean notes in wallets and purses.
The Bundesbank announced in early November that reports of bank notes worth between five euros and 100 euros disintegrating began to be received in the summer.
A 2003 report by the Institute for Biomedical and Pharmaceutical Research in Nuremberg found that 90% of German euros were contaminated with cocaine.