‘I see them the whole time’: The problem of fakes in the art market

Art forgeries are more common than you might think, but stories about them often stay underground. 

That's according to lawyer Helen Mulcahy, a partner at legal firm Fieldfisher who specializes in art and fraud.

"They often don't come to light," Mulcahy told CNBC by video call. "Reputation in the art market is so important … not many people like to go to court," she said. Cases are often settled in private in part because of the "embarrassment factor" for a buyer.

Mulcahy advises wealthy clients on the checks they need to make when buying art, including attribution and provenance — namely, who has owned an artwork and when and where it has exchanged hands. Such information is detailed in exhibition records, auction catalog references, certificates or other documents.

"Provenance also should describe the medium, the dimensions, the date it was made. And sometimes it's not always the artist, it might be attributed to the artist, it might be the school, the circle of, so there'll be sort of levels down," Mulcahy said. Checking provenance is relatively straightforward on the primary market, where collectors buy from a living artist's studio or representative, but less so on the secondary market, which refers to the resale of works.

Tom Rooth, an artist and dealer who spent more than a decade at high-end auction house Christie's and left in 2017, said he sees fakes frequently. "I see them the whole time. You know, I can go onto an auction website now [and be able to] spot fakes … they are sort of everywhere," he told CNBC by phone.

"[It was] a great training to work for an auction house because … you get emailed images, by people of their paintings, asking for valuations. You're so used to seeing pictures on a screen and