The madness is continuing days after last weekend’s Chester Heritage Festival with official Pokémon GO festival maps, passports and certificates selling for up to £150 on eBay.

Thousands of players descended on Chester from near and far as they captured virtual monsters on their smart phones at historic sites transformed into 120 PokéStops.

The event was the result of a unique partnership between Chester-based Big Heritage, Niantic Labs – the developer and publisher of the global games phenomenon Pokémon GO – and The Pokémon Company International.

Pokemon passports, leaflets and certificates are being sold for up to £150 on ebay.

Now free literature given out on the day such as the festival map and quiz, limited edition certificates and a passport that required special stamps after visiting re-enactors such as Romans and Vikings are being sold on auction site eBay.

All three items, including a fully stamped passport, are being sold by two vendors for £150. But there are other deals at £15, £25, £50, £55, £65 and £100.

Chester’s world exclusive event coincided with a first anniversary festival for the worldwide game held in Chicago where server and networking issues spoiled the fun.

In contrast, the Chester event has been hailed a massive success with organisers estimating it brought £3m spending power to the city.

Pokemon passports, leaflets and certificates are being sold for up to £150 on ebay.

Every corner of the city appeared to be packed with hundreds of young people and families with eyes glued to their phones.

Chester played host to Pokémon GO players, known as ‘trainers’, from the surrounding area, the rest of the UK and around the globe including a young man who came all the way from Chile.

The aim was to encourage community engagement and education alongside the fun and games.

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And the event coincided with the annual Chester Heritage Festival which also included reenactments and banner making at Chester Castle with other happenings at the amphitheatre, on the Rows, Grosvenor Museum and in Town Hall Square.

Dean Paton, managing director of Big Heritage, offered this tantalising promise: “I can confirm this won’t be the last thing we are doing with Niantic and Pokémon GO. Exciting times ahead.”