A German pensioner flushed bundles of old banknotes down the toilet because he thought they were worthless, according to police in the northern city of Kiel.

Police said he dumped some 60,000 deutschemarks - which the euro replaced in 2002 - into the bowl, unaware they could still be exchanged for about euro30,000 ($49,833).

Sewage workers recovered about half the wringing currency from the 64-year-old's plumbing. The remaining notes created a bottleneck in local sewers, where most were fished out.

Police said the man lived in austere circumstances and had dried out the notes and taken them to a bank.

It was unclear if he had laundered the money first.