Italian police have linked “Black Death,” a crime syndicate that operates on the dark web, to the abduction of British model Chloe Ayling.

According to reports, the model who returned to the United Kingdom on Sunday was kidnapped July 11 in Milan, Italy, by an operative of the group, which notoriously claims to buy and sell abducted women through auctions on the mysterious dark web, where human trafficking is rampant.

Police arrested Lukasz Herba on July 17, when he accompanied Ayling to the British consulate in Milan, according to CNN.

However, it was not clear why Herba was taking her to the consulate. The Sun reported that when Herba was arrested, police found a leaflet with drawings of doctors wearing masks from the time of the Black Death plague in the 1300s, an image associated with the group.

Model abduction by Black Death Above is recreation of the scene by the state police of Italy that shows how model Chloe Ayling might have been put in a bag when she was abducted. Photo: Polizia di Stato

Herba was accused of trying to sell Ayling for 300,000 euros (270,000 pounds) and demanding payment through bitcoin, claiming action on behalf of the Black Death group, a press release by the Italian police said. A report by the Daily Mail added he allegedly confessed to having kidnapped the model.

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Daily Mail also published a letter that was purportedly sent by Black Death to Ayling after she was released, stating she being freed was a “huge generosity.”

According to the report, the letter also said: “A mistake was made by capturing you, especially considering you are a young mother that should have in no circumstances be lured into kidnapping. Second important factor (sic) you are very well aware of is your overall protection by one of our main and very well respected men who made a very clear and solid stance in your case."

It added: “You will, upon your landing in your home country cease any investigation activities related to your kidnapping. You also agreed to sneak a pre-determined set of information in to the media and we will expect to see evidence that has been done in the near future.”

The group is reported to have existed for a long time, but the kidnapping is the only crime that has been linked to it by authorities so far. Daily Mail added the group operated in areas including bombing, drug dealing, human trafficking and arms dealing.

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In a report, Joseph Cox, a contributor for Vice’s Motherboard, recounted his experience online with the organization after he found information about it on Reddit, and said: “I wrote back to Black Death, claiming that I acted as a middleman between businesses. They didn't buy it. 'Nice try Europol,' read the reply.”

According to CNN, Italian investigators said Herba had already organized several online auctions for abducted girls. The website for these auctions included a description of the victim and a starting price. It is, however, not clear if the photos of the women put up by the group are authentic.

Ayling was lured to Milan for a fake photoshoot July 11 and was drugged with ketamine. She was then stuffed inside a “dark bag.” She was then taken to a house in a remote area, from where Herba allegedly tried to sell her on the internet, CNN reported.