They are the mysterious online crime syndicate that claims to be able to offer 'services' including assassinations, bombings, arms dealing and trafficking.

But Black Death has come under the spotlight after it was linked to the kidnapping of a British model, 20, in Milan and even gave her a note explaining why she was being released.  is unclear whether police found a physical copy of the letter or whether it was on a computer, but it said the model had been captured 'by mistake' and should 'under no circumstances' have been kidnapped, adding one of its 'well respected' members pleaded her case.

Black Death offers the sexual services of women for auction on the dark web and are very hostile to people asking questions. 

Technology writer Joseph Cox previously tried to investigate Black Death in 2015 when he attempted to enter a human trafficking auction to discover how the syndicate worked and whether they were legitimate.

After finding them through a link on Reddit, he posed as a customer and asked to be involved in the auction, sending an encrypted email stating 'I'm interested in the girl, want to see more photos first'. Writing for Motherboard he revealed a girl called 'Nicole' was put up for auction starting at £115,000 alongside pictures of a blonde woman who was topless and tied up to a wire frame by ropes with her arms behind her back.

Another woman was put on auction with bids starting at £140,000, Mr Cox wrote to them claiming he was a middleman acting for another business.

Their response was 'Nice try Europol' and after several more emails in which he claimed to possess hundreds of thousands of dollars in Bitcoin, they still rejected him, emailing him 'Do not bother us again', before the link to the site stopped working.    

• Black Death group explained why they released British model in a note to her
• They said they were being 'generous' and freeing her 'because she is a mother'
• But they warned her to be 'respectful of them' and not go to the authorities 
• Group surrounded in mystery but claim to offer wide range of criminal services
• They say they offer assassinations, drug dealing, bombings and arms dealing