A retiree in northern Germany flushed some 30,000 marks (euro15,300, US$18,900) down the toilet, believing the old bank notes were worthless, police said.
Officials were alerted by a blocked pipe in the northern city of Kiel. A cleaning company employee extracted soggy bundles of bank notes, but more money got away as the water started flowing again.
Investigators then discovered that the retiree had reported a blocked pipe at his house the same day. They visited the "slightly bewildered" man at his apartment, and he confirmed that he had flushed the money away, a police statement issued late Wednesday said.
The 64-year-old "was of the opinion that mark notes no longer had any value," it added. He still had another 30,000 marks at the apartment, as well as 14,000 euros (US$17,300) in euro bills.
Police accompanied the retiree to a bank, where he deposited the money.
Euro notes and coins replaced 12 national currencies in 2002. Europeans can still exchange the old money at their central banks.