Japanese police have arrested six men whom they accuse of orchestrating a "one-click fraud" scheme using a computer virus.
According to the Mainichi newspaper, the virus displayed pornographic pictures that could not be erased without paying a fee to the alleged creators.
A news report by Japanese TV service NHK put the alleged erasure fee at between ¥70,000 and ¥120,000 ($A845 $A1450).
The virus is thought to have infected up to 1.1 million computers and netted its creators about ¥600 million (almost $7.2 million).
Kyoto Prefectural Police were trying to build a case against those arrested, the news reports said.