An investigation into the online sale of more than two dozen unauthorized Banksy art prints is underway in the U.K.

An exposé by the Art Newspaper revealed that at least 25 illegal art prints by the up-and-coming British graffiti artist have been sold at artificially inflated prices on eBay.

Banksy's politicized, often controversial artwork has been growing in prominence, selling for escalating prices, featured in high profile exhibits and even targeted by thieves.
(Matt Cardy/Getty Images)

The artist, his dealer Steve Lazarides and the directors of Pictures on Walls (POW) — the company that produces his prints — have expressed concern that they and members of the public "have been victims of criminal behaviour."

"It appears that in spite of strict fiscal controls and strict controls of the physical prints that 25 bad prints have been sold on eBay," they said in a statement.

A source who claimed to have collaborated in the online auction scam told the Art Newspaper that the fraud dates back about a year, as buzz was building for Banksy's artwork.

The story alleges that three employees of POW, including one who has since left, distributed unauthorized Banksy prints to others, asking them to sell the illegal artworks online .

It is unclear whether the prints were standard overrun production copies that were earmarked to be destroyed or new prints created in addition to limited-run artworks.

The sellers were also allegedly told to create false eBay accounts so that they could make artificial bids to increase the prices of the fraud prints.

The source said that about 20 illegal works were posted on eBay, but that the fraud could extend up to 100 prints.

Both the police and the online auction site have begun investigations, according to the newspaper.

Banksy, Lazarides and POW have invited current print owners concerned about the provenance of their artwork to come forward.

In the past few years, Banksy's politicized, media- and pop culture-inspired artwork has gained an increasingly large fan base. His oeuvre spans prints, sculptures, paintings, graffiti murals around Britain, doctored CD packaging and multimedia installations.

In February, a Banksy canvas sold for nearly $240,000, a new record for the Bristol-born artist who has managed to keep his true identity a secret. Just two months later, his painting Space Girl and Bird, commissioned for a Blur album cover, set a new record when it sold for about $581,000 at a subsequent auction.

A high profile exhibit that recently showcased Banksy's artwork alongside that of Andy Warhol also drew strong attendance in London.