Blackmailers have threatened to use the deadly Ebola virus as a biological weapon unless the Czech Republic pays a ransom of €1m (£788,000, $1.26m) in bitcoins, Daily Mail reports.
The blackmailers warned the Czech authorities that failing to comply with their demands would lead to the release of the disease in Prague as well as other cities.
They also threatened to hold a 'viral' social media smear campaign.
"If you don't answer this letter, we will send press releases to media and inform people on social networks such as Twitter, Facebook and Youtube to let them know how negligent the Czech offices are," they said.
The blackmailers wanted Czech officials to pay the money in three parts. The first was supposed to be paid on 3 November, a second on 5 November, and a third after they handed over the infected material.
The warning was sent in anonymous emails to the cabinet offices of the Czech government.
The government would require about 4,000 bitcoins to pay the ransom at current prices. It is not known whether the government possesses that number of digital currency.
The Czech Republic's interior ministry issued a public statement saying that "the culprit or culprits are using very sophisticated communication methods, making it difficult to trace them".
Czech police say they are not taking the letters and blackmailing seriously.
"The only intention of the blackmailers is to cause a panic," a statement from the police said.
There have been concerns that bitcoin, an electronic currency, is aiding terrorists and blackmailers, as it enables them to receive funds anywhere in the world almost anonymously and immediately. Once bitcoin is sent to another person, the transaction cannot be frozen or reversed.
Ebola virus as a biological weapon? What!