Works by Banksy are disappearing from U.K. auctions as collectors shy away from paintings by graffiti artists in the financial slump.

British regional auction houses have canceled specialist sales of urban art in London, while some of their bigger rivals’ catalogs have few stenciled works by Banksy, who was born in Bristol, west England, and keeps his identity a secret.

Falling prices and rising failure rates for Banksy works earlier this year have made sellers reluctant to test the market with higher-value paintings. Auction prices for contemporary artists generally have dropped between 30 and 50 percent with the crisis, according to dealers.

“There’s no point flogging a dead horse,” Ben Hanly, contemporary-art specialist at the Edinburgh auctioneers, Lyon & Turnbull, said in an interview. “The core collectors have been decimated. Young City types don’t want to spend 20,000 pounds ($32,690) or 30,000 pounds on trendy art at the moment.”

There were no Banksy paintings to be seen at Sotheby’s, Christie’s International’s and Phillips de Pury’s evening contemporary-art auctions in London in June, or at Bonhams’s Vision 21 sale on July 1. Meanwhile Lyon & Turnbull and Berkshire-based auctioneer Dreweatt Neate both dropped standalone events.

Five Banksy sprayed-stenciled works, ranging in estimate from 7,000 pounds to 18,000 pounds, failed to sell at Lyon & Turnbull’s April 24 contemporary-art auction in London. The company’s October sale will contain a higher proportion of works by established 20th-century British artists, said Hanly.