Game Boy Advance cartridges carry no region protection, and with the UK launch of the eagerly awaited Pokemon titles still two months off, many gamers and indie retailers are turning to the US version of the games - which was released several weeks ago.
Some importers are even selling the US edition of the games for a lower price than the titles will launch at in the UK when they finally arrive on July 25th.
Speaking to UK trade paper MCV, Nintendo UK general manager Andy Williams commented that "Nintendo is monitoring the situation closely and is prepared to take legal action against importers and retailers should the number become significant. The games currently on sale are not intended for sale within the EEA."
However, Williams does not believe that the game is being imported in significant enough numbers to cause serious damage to the UK launch.
Nintendo is likely to face similar problems with future GameCube titles, thanks to the availability of Datel's Freeloader, a product which allows gamers to play imported titles on their GameCubes without any internal modification.
Of course, rather than cracking down on its most loyal and hardcore fans, Nintendo could always do itself a favour and make some attempt at sorting out the disgraceful state of its European release schedule, which currently sees major titles being released in Europe several months after their US debut.