How much foreign currency do you have stashed in your drawers?
The study* discovered that 56% of British men hoard an average of Â£32.76 each, in various currencies.
It means that the equivalent of Â£46million lays among other forgotten items like redundant phone chargers, watches, used batteries and old keys.
Euros make up the vast majority of money tucked away in bedside drawers, followed by US dollars and Australian dollars.
Other forgotten but potentially valuable items kept with holiday currency are watches, with 20% of men saying that two lay forgotten in the drawer.
With many watches selling on eBay for between Â£20 and Â£300 on average, the bedside cabinet looks to be a goldmine of hidden treasure.
Old phones are one of the most commonly-hoarded items, with 80% of men having at least one old ones stashed away, even though models like the iPhone 5 and Samsung Galaxy A5 are worth about Â£56 from companies such as Envirofone.
Other junk that men most commonly hoard around the house are:
* Instruction manuals - 91%
* Screws and small hardware - 87%
* Old keys - 74%
* Membership cards - 73%
* Old magazines - 66%
Vlatka Lake, marketing manager at self-storage company Space Station, which commissioned the research, said: “The amount of foreign currency that’s laying among things like old batteries and keys is astonishing.
“Everyone hoards old junk to some extent, but it seems that men have a real knack for keeping valuables together with things that they’re unlikely to ever use again, in the ‘out of sight, out of mind’ drawer.
“Some items, like expensive watches, can become more valuable over time, so it’s best to keep them in a safe place.
"Otherwise, though, the bedside table drawer is one of the best places to start when decluttering your home.”