They were all the rage in the late 1990s as playgrounds in schools up and down the country became Pokemon card swap shops - but if you managed to hang onto your old Pokemon cards, some of them are worth thousands and thousands of pounds today.

Pokemon was thought to be a fad when it exploded in popularity in 1999 to 2000, spawning a TV series, several films and a run of thousands of Pokemon cards as well as the GameBoy games. Fast forward 25 years, and Pokemon is now the single most lucrative franchise in the world, eclipsing any Hollywood franchise and The Pokemon Company is worth a staggering $10.8billion.

If you want to cash in on a little bit of that wealth yourself, all you need to do is dig out your old Pokemon card collection from the attic or garage - because some of them are worth as much as £7,000 per card.

In fact, Pokemon cards are so valuable today that just last two weeks ago, Greater Manchester Police arrested a man after they found £250,000 worth of stolen Pokemon cards in a flat. The cards were worth £100 to £560 each and police set about trying to return the stolen cards to their original owners following the raid.

According to PokeCardValues.co.uk, the most valuable Pokemon card in the UK today is Base Set Charizard. This has sold for £7,480 in a confirmed sale - not just someone listing it and trying their luck, someone actually paid £7,480 for this card. Released in the first set of Pokemon cards back in the late 1990s early 2000s, known as base set, a shiny Charizard card with the numbering 4/102 will always fetch at least £4,083 if it’s in good condition, according to the site which tracks real sales of Pokemon cards on Trading Card Game websites and eBay.

Second is Espeon Star, released in Pop Series 5, which sold for £3,250 on eBay.

Among other valuable cards are Base Set Venusaur shiny first edition, also from the 1990s, which is worth up to £751, and Base Set Gyarados, worth £300.

Another card, Pikachu Star, sold for £1,535. Rounding out the most valuable are Torchic Star (£1,857), Tropical Beach Promo (£3,250) Mewtwo Star (£1,487) and Shining Charizard from Neo Destiny (£1,486).

With just a few cards potentially worth thousands per card, you could quickly amass a huge sum just from selling a few cards from a shoebox or binder that’s been gathering dust.

The first Pokemon game was released in Japan in 1996, before coming to the US in 1999 and the UK in June 2000.

The franchise is still going strong: on Thursday, June 5, Nintendo is releasing an update for the latest games, Pokemon Scarlet and Pokemon Violet, to allow for upgraded graphics on its latest console, Nintendo Switch 2, while the latest series of Pokemon - Pokemon Quest - is coming to Netflix this June having already been on BBC iPlayer.