A retired decorator in England has become a millionaire by selling Pokémon cards he had kept in his attic, according to the BBC, IGN and Kotaku.

The collection sold at Ewbank's, an auction house in Surrey, on Wednesday for £1.56 million, the BBC reported. IGN put that at about $2 million. Kotaku said it came to $2.09 million.

The man is from Woking, southwest of London, and asked not to be named, the BBC reported. He said he had no idea the cards had value until he read in his local paper that a single card sold for more than £6,000.

"I know people always talk about finding treasure in the attic, but in my case that is literally true," he said, according to the BBC.

His son started swapping the cards at school in the late 1990s, the BBC reported. The man said he thought they looked nice and might be a good investment. He bought some full sets on eBay from a seller in Malaysia, the BBC said. The cards were kept sealed in binders in the attic after his son lost interest.

Ewbank's said "jaws hit the floor" when the man brought in his 42 sets, the BBC reported. "When we saw what he had – all in mint condition – we couldn't believe it," said James Spooner, the firm's head of trading cards. The auction house said it was its most successful sale in more than 30 years.

The top lot was a full set from the Legendary Collection, the BBC reported. It had been expected to bring £15,000 to £20,000.

Andrew Ewbank, who ran the sale, said at the end of the sale that he was "going for a lie down", the BBC reported. He said Pokémon is "booming" as people who grew up with it now have some money to spend. "It's about bringing back those memories of childhood," he said.

The auction house said the total beat a record set on October 9 in London, when a sale at Stanley Gibbons brought £872,000, the BBC reported. IGN noted that a single rare Pikachu card sold for $16,492,000 in February.

What we know: The collection sold for £1.56 million on Wednesday.
What we don't: How much each lot brought, since the outlets give some different prices.