The euro may have come into general circulation in January 2002 but people are still handing old guilder notes to the central bank to be converted, broadcaster NOS said on Tuesday.

Last year, 97,000 guilder notes were handed in at the bank with a total value of €4m. Coins have not been exchanged for euros since 2006.

‘Guilder notes often turn up in sad situations,’ spokesman Rob Ruizendaal told the broadcaster. ‘We once had a plasterer who had put notes behind the wallpaper in a room. He ended up in a care home and his children found the money when they stripped off the paper years later.’

Notes also turn up hidden behind shelves or in magazines and these are sometimes ‘considerable sums’ Ruizendaal said.

People wishing to swap old guilders have to provide ID and fill in a form explaining why it has taken so long to bring them in. And if the bank feels that something is not right, it will refuse the swap and bring in investigators, NOS said.