When imagining law enforcement officers investigating and searching for cyber criminals or evidence about their activities, the last thing that you can probably envision is them searching for a stray cat.

But that was exactly what detectives of Japan's National Police Agency recently did as the last step in a complex "treasure hunt" started on New Year’s Day by a person (persons?) who is allegedly the mastermind behind the so-called “Remote Control Virus”.

The malware in question was instrumental in staging a continuous campaign of death and bomb threats sent to airline companies, kindergartens, schools, law offices, broadcasting networks and shrines.

The investigation into those threats revealed that a yet unidentified individual or group has been using the malware to compromise random Internet users' computers and sending the death threats from them without the users' knowledge.

In a particularly embarrassing episode of the investigation, the Japanese police arrested four of those unsuspecting individuals and extracted "confessions" from them, only for other institutions to receive threats containing details that only the real criminal behind the scheme would know - while the four were in custody.

Having released them, the police continued the investigation and, finally, on New Year’s Day, the cyber criminal sent messages again. They were riddles this time - riddles designed to make the police jump through hoops in order to locate and capture a stray cat with a memory card attached to its collar.

The card supposedly contained information about the aforementioned malware that only its creator would know.

AFP's report does not say whether the recovered card did, in fact, contain anything of that sort, but Wired reports that the police has, for the first time in Japanese history, offered a reward of 3 million Japanese yen (around $34,300) for the capture of the criminal, whom they believe to be proficient in the C# programming language and capable of keeping his Internet activity hidden.