Six persons have been arrested in Valencia, Spain, after police broke up a criminal group that was selling crudely copied paintings ascribed to painters such as Francisco de Goya, José Benlliure y Gil, and Nicolás Falcó over the internet.

The inquiry started when questions surfaced about the origin of Falcó’s The Adoration of the Three Wise Men, which had been purchased for €18,000 (£15,000) and was being resold for €45,000.

The picture, which was advertised as a 16th-century original, turned out to be a forgery, leading authorities to a ring of forgers selling more than 30 paintings online. Officers confiscated 27 works worth €1.2 million and discovered a crude counterfeiting ring replete with forged certificates of authenticity. One of them was a picture claiming to be An Immaculate Conception by Goya, with a €900,000 asking price.

The Valencian regional administration claimed in a statement that “[the gang’s] methods were as simple as placing a small piece of paper over a signature to swap it for another, reusing both sides of a canvas, and imitating cracked paint by burning the canvas with a blowtorch.”

Experts from the Valencia Institute of Conservation, Restoration, and Investigation, as well as the Valencia Museum of Fine Arts and the city’s Benlliure Museum, were summoned.

Eighteen of the 27 pieces were discovered to be fakes, two to be genuine prints, and four to be useless ornaments. Three others were not found to be forged, according to investigators.

The regional justice secretary, Gabriela Bravo, stated the police had “successfully shut down a new illegal network that was buying and selling art and offering more than 20 works on the black market.”

Fraud charges were brought against seven members of the group. Three were sentenced to ten months in prison, three to three months, and one was acquitted.

Three false paintings claimed to Goya, El Greco, and Amedeo Modigliani were confiscated by Valencian police in March and were being sold on the underground market for €12.5 million.

“The resale of forged paintings is a persistent problem in the art market,” a police spokeswoman stated at the time. “It concerns not only the police, but also collectors, art dealers, and artists’ descendants.”

Thanks to at The Guardian whose reporting provided the original basis for this story.