Users of the drug crystal methamphetamine may be causing euro banknotes to disintegrate, German police have told Der Spiegel magazine.Now, the European media is obsessed with connecting euros and drugs.
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About 1,500 banknotes have crumbled after being withdrawn from cash machines, German banking officials say.
I'm no mathlete, but I'm thinking that this study needs a larger sample. (Of euros, not cocaine.)
Cocaine on '100% of Irish euros'
By James Helm, BBC News, Dublin
One hundred percent of banknotes in the Republic of Ireland carry traces of cocaine, a new study has found.
Researchers used the latest forensic techniques that would detect even the tiniest fragments to study a batch of 45 used banknotes.
The scientists at Dublin's City University said they were "surprised by their findings".
Some of the notes had such high levels of cocaine on them that it is thought they were used to snort the drug.
Others had much lower traces and may have been cross-contaminated, perhaps in the wallets or pockets of users.
Growing cocaine use
The results fit with scientific findings from other countries such as the UK and Spain where cocaine has also been found on a high proportion of notes.
Cocaine particles stick to the cotton that is contained within the notes.
Cocaine use is thought to be growing in Ireland. Professor Brett Paul, whose paper was published in a journal of the Royal Society of Chemistry in the UK, said it demonstrated how widespread the use of cocaine is.
The study also found that higher value banknotes, such as 20 and 50 euros, were more likely to contain greater traces of the drug.