Could your kids be playing with a hidden fortune?
According to new data, households across the UK may contain more than £50million worth of highly-collectable LEGO.
The iconic building block toy has seen an average year-on-year increase of 12 per cent in value since the millennium, according to Zapper.co.uk.
The company estimates that a potential £54m fortune – based on average LEGO trade-in prices – is sitting in attics, disused toy boxes and cupboards across the UK.
In total there are around 48 million pieces in the UK – enough to build a life-size replica of Buckingham Palace.
The company says that loose LEGO still holds value and can be a great money maker for enthusiasts.
However, it's the rare and collectable items which are causing the spike in value, with some figurines and sets selling for staggering amounts.
LEGO'S MOST VALUABLE FIGURINES
1. Mr Gold Figurine – £1,799.99
2. The Hobbit: Azog – £1,756.66
3. Star Wars: Boba Fet (Cloud City) – £280
4. Guardians of the Galaxy: The Collector – £278.27
5. DC Legends of Tomorrow: Atom – £170
6. Star Wars: White Boba Fet – £170
7. Star Wars: Lando Calrissian (Cloud City) – £115.94
8. Lord of The Rings: Bilbo Baggins – £75
9. Harry Potter: Professor Trelawney – £59
10. Harry Potter: Beletrix Lestrange Dual Face – £49.99
11. Harry Potter: Hagrid – £49
LEGO'S MOST VALUABLE SETS
1. Star Wars: Ultimate Collector's Millennium Falcon – selling for £3,113.02 (RP £342.49)
2. Café Corner – selling for £2,499.96 (RP £89.99)
3. Harry Potter: Hogwarts Castle 5378 – selling for £1,617.46 (RP £69.99)
4. Harry Potter: The Knight Bus – selling for £221.03 (RP £29.99)
5. Star Wars: Death Star 10143 – selling for £3,189.99 (RP £249.99)
6. Green Grocer 10185 – selling for £1,629.95 (RP £99.99)
7. Lego Batman: The Tumbler, Joker's Ice Cream Surprise – selling for £679.99 (RP £39.99)
8. Emerald Night Train Set – selling for £989.95 (RP £69.99)
Patrick Neill, chief executive of Zapper, said: "There are more than 48 million pieces of LEGO in the UK, which means the potential for re-sale is huge.
"If the whole of the UK were to cash in on their collections, it would mean seriously big money.
"Of course, that's not going to happen, but what our data does reveal is that there's huge potential for those with LEGO collecting dust to make some fast money."