Any hopes that one man may have had of cashing in on a stencil purportedly painted by Banksy were dashed when he took it onto the Antiques Roadshow for valuation.

The unidentified man claimed to have removed the piece — which looks like one of the artist’s trademark rats ― from a wall on the seafront in Brighton, in the early 2000s.

“It looked loose. Went over, pulled it off basically, a little bit of a tug,” the man told one of the show’s art experts, Rupert Maas, in the clip.

“I know what it is,” the man added. “It was around 2004, basically trying to get a valuation of it.”

Maas quickly dismissed the idea of striking it rich with the work.

“The thing about Banksy, and he’s not the first to have done this, of course, is that he manages his brand very, very carefully indeed,” Maas explained.

“There’s a website where you can go in and you can apply for a certificate of authenticity of his work,” he continued. “And then he, or his team, will issue one if they think that, first of all, it’s authentic, and B, they think that it has not been removed from the public domain for which it was painted, and into the private. Now, that might be a reason not to issue a certificate of authenticity.”

The service that authenticates Banksy’s works is called Pest Control.

The man told Maas he had applied for authentication but “they said they couldn’t claim it was an original Banksy.”

“I know it’s real,” he added. “Because Brighton was hit quite a bit by Banksy when he was down there around that time.”

Maas left the man with some food for thought:

I think the message here is that, if you do see a piece of graffiti art out there, leave it, leave it for the public. I’m not lecturing you. I’m just saying, without that certificate, it’s just very difficult to sell. With it, it might be worth £20,000 [around $26,000]. Without it, you’re nowhere.

It’s unclear whether the piece was actually by Banksy, although it does bear all of the street artist’s hallmarks. Banksy’s publicist did not immediately reply to HuffPost’s request for comment.

A message did appear on the Pest Control website, however, that said the Antiques Roadshow segment sums up “rather well” its policy of verification. The organisation also shared the clip on YouTube, above.

Some social media users criticised the owner for hawking the taken Banksy and others speculated he could have been a stooge from Banksy’s team, given the artist’s storied history of satirically critiquing the art world and the 2011 television show. The Antics Roadshow, which he directed about pranks and art activism.

Although the unidentified man appears unable to cash in on the piece, several of the artist’s previous works have been removed from the walls he originally painted them on and sold for high prices at auction.

On canvas, meanwhile, Banksy’s works now regularly fetch six-figure sums. 

His depiction of British members of Parliament as chimpanzees sold last year for about $12.9 million. 

On Saturday, Banksy appeared to confirm on Instagram that he was behind a mural of a girl hula-hooping with a bicycle tire, next to a trashed bike, in Nottingham: