Chinese police have detained four suspects for allegedly photocopying and selling comic books with prurient content, according to anti-illegal publications authorities. Investigations started in September 2012, when the office received tip-offs on a large number of illegal comic books in storage in a suburb of Beijing, said a statement released Friday by the National Anti-Pornography and Anti-Illegal Publications Office. On September 25, 2012, two suspects surnamed Hu and Du were seized as police stormed the storage unit, with over 80,000 self-published books priced at a total of three million yuan (491,803 U.S. dollars) confiscated, the statement said. These books were found to be photocopied from Japanese comics with the words translated into Chinese. They were intended to be sent to provinces including south China's Guangdong, Sichuan and Guizhou for sale. Further investigations revealed that Hu and Du served as publishers of the books, while another two, who were responsible for printing and packaging, were detained late in 2013 after being at large for over a year. The office urged Beijing authorities to strengthen further management of the case and severely punish violators while calling on other regions to uncover similar wrongdoings to clamp down on books harmful to the health of young people.