The Metropolitan Police has made three arrests in connection with the distribution of malicious code, known as ransomware.
It is alleged that the two men and one woman, aged between 26 and 34, applied software designed to convince computer users that their online activities were being inspected by the police.
The individuals currently being held in custody all hail from Stoke-on-Trent, and are being detained on suspicion of conspiracy to defraud, money laundering and possession of items for use in fraud.
Their malware would cause an infected machine to lock and then prompt a warning message, which through the use of relevant logos, was constructed in such a way as to appear like it was issued by the Metropolitan Police and the Police Central e-crime Unit (PCEU).
The message's contents explained that the computer had recently been used to download illegal materials, and would require a £100 on-the-spot payment in order for it to be unlocked.
"The arrests shows we are determined to combat this type of crime," said detective inspector Jason Tunn, of the PCEU. "I remind all computer users that police do not use such a method to impose or enforce fines, so if you are confronted by such a page do not enter any of your details."
Victims are instead advised to consult a nearby computer repairs shop and contact the police.