A man who appeared on the BBC's Antiques Roadshow, hoping to hear the value of his Banksy artwork, ended up receiving a rebuke from the show's specialist and Banksy's team.
The unidentified man told specialist Rupert Maas that he found the artwork—featuring Banksy's name and a rat stencilled on a steel plate—on a seaside wall in Brighton, England, around 2004.
"It looked loose" so "[I] went over, pulled it off basically," the man said, per Artnet News. Maas then explained that Banksy issues certificates of authenticity for his works so long as they haven't been removed from the public domain.
The owner of this work said he applied for a certificate but was denied. "I think the message here is that, if you do see a piece of graffiti art like that ... leave it for the public," Maas said, noting the work might've been worth $26,000 with the certificate.
A section about certificates of authenticity on Banksy's website has since been updated to include a link to the Antiques Roadshow segment, which Banksy's team shared on YouTube.
"The Antiques Roadshow sums it up rather well," the site reads. Artnet notes social media users "roasted the owner like a butternut squash," though some have suggested the man was actually hired by the secretive artist, who directed a 2011 documentary about activist pranks called The Antics Roadshow.
Meanwhile, a Banksy work created around the same time as the metal plate sold for $9.8 million at a Sotheby's auction on Wednesday. "Show me the Monet," a 2005 take on Monet's "Bridge over a Pond of Water Lilies," showing shopping carts and a traffic cone submerged in the famous pond, is now the second-most expensive work by Banksy, reports CNN.
This article originally appeared on Newser: It Has Banksy's Signature. Here's Why He Won't Authenticate It