Dirty money? Swiss investigators are perplexed about who flushed tens of thousands of euros down toilets in Geneva. And why?

Bundles of shredded 500-euro notes, worth about $120,000 or 100,000 euros, were found clogging toilets at a bank and three nearby restaurants. 

The high-value euro notes are due to be discontinued in 2018 over fears they are being used in illegal activities, including money laundering and sponsoring terrorism.

The notes will remain legal tender, but the European Central Bank will stop producing them following a European Commission inquiry into their use.

Destroying legal tender is not an offense in Switzerland, but police want to know the circumstances that would lead someone to flush money down a toilet.

The Tribune de Geneve newspaper, which first reported the unusual deposit, said it appeared the money belonged to unnamed Spanish women who had placed it in a safe-deposit box at the bank.

Police have not disclosed the women’s identities and are unsure why they would have wanted to dispose of the euros.

“We are not so interested in the motive, but we want to be sure of the origin of the money,” said Vincent Derouand, spokesman for the Geneva prosecutor’s office.

“Clearly, it’s very surprising,” he said.