A Colorado charity shop is auctioning off a purported lithograph of a Salvador Dalí work that it received from a mystery donor.

But the Goodwill shop in Grand Junction says it does not plan to verify the work’s authenticity.

A customer recently pointed out the signature on the print of The Discovery of America by Christopher Columbus, which was numbered 168 out of 300.

Manager Bill Atwell told Denver’s KMGH-TV he did not know who donated the piece. He said the store was “here just to raise money for our programmes” and it was not going to pay an expert to determine if the work was authentic.

Instead, he said, the store, operated by Goodwill Industries, would let people bid for the piece and determine its value on their own.

As of Tuesday night, bidding had climbed to $550 (€398.5).

The original painting is in the Salvador Dali Museum in St Petersburg, Florida.

Mark Winter of Art Experts in Daytona Beach, Florida, which appraises and authenticates artwork, said it was possible the piece in Grand Junction was real because it was numbered.

If it is, it could be worth $2,000-3,000 (€1,449-€2,173).

But he warned there were also more than 200,000 fake Dalí lithographs – and there was a market for them too.

“They all have their following,” Mr Winter said.