LONDON—The increased art-market success of British street artist Banksy has led to the creation of a controversial new organization called Vermin, Artnet reports. Vermin was created to authenticate Banksy's street works without the approval of the artist and is in competition with Pest Control, the authentication body currently headed by Holly Cushing and operating with Banksy’s consent.

Vermin is partly the result of complaints lodged against Pest Control, including the criticism that it offers almost no information on its Web site. In response, the organization added an information page to the site, explaining that it "does not authenticate street pieces because Banksy prefers street work to remain in situ and building owners tend to become irate when their doors go missing because of a stencil." Pest Control adds that since the beginning of this year, the group has identified 89 street pieces and 137 screen prints as falsely attributed to Banksy. The artist advises "anyone wanting to purchase one of his images to do so with extreme caution."