Derbyshire police are warning people about a new scam where emails are sent threatening violence unless a ransom is paid in Bitcoin.
The warning comes after the force's cyber-crime team has received several reports of scam emails.
Derbyshire police said: "This is a scam. Do not pay the ransom. We don’t believe the threats to be genuine."
The force has shared an example of one of the scam emails:
"Read this message carefully, since it can be the last in your life.
"People are by nature envious. Given the fact of successful development of your business, people (your competitors) paid me 30,000 £ for your severed hands.
"It's not the first time I've done this kind of work, but I'm already tired of these envious ******** and your life will be the last one I'll take or will not do, it's up to you.
"Under normal circumstances, I would just do the work for which I was paid without going into the details, but I'm going to get away from it and go on a long-awaited vacation.
"You have 2 options for solving this situation.
"Accept my proposal or discard.
"You pay me 10000 £ for safe your life and you receive all the information about the customer with whom you apply to the police and thus you save your life and the lives of your relatives.
"The second option is you ignore my proposal and turn to the police, but by the same token you will only postpone your judgment day, even if I can not do the work, then somebody else will do it, not within a week and say in a month or half a year, but order for your head will be fulfilled sooner or later.
"Thus, you will be afraid of every rustle, walk around looking and thinking that you are being persecuted.
If you want such a life, your choice, but if I were you, I would think very well.
"Tickets to England have been taken for July 28, and you have exactly 3 days to transfer money to an anonymous account bitcoin **********.
"The last time I can check it 28th before flying to you.
"In the event of receiving a reward, I will not come to take your life, but will also pass all the information about your customer and you can protect yourself, otherwise you know the consequences.
"The well-being of the future life depends on your choice.
"Think about your life, you family."
If you receive a scam email, call Action Fraud on 0300 123 2040.