South Korea's top portal operator, Naver Corp., said Monday it has cracked down on illegal websites that share its online comics with its "Toon Radar" program, claiming it will expand surveillance to safeguard intellectual rights.

Naver said the owner of a South Korean pirate website was indicted last month for infringing on intellectual property and distributing its online comics to attract visitors while posting advertisements for gambling and pornography.

"The Toon Radar program lent support to the investigation," Naver said, claiming the company is continuing its online surveillance. The program monitors more than 100 pirate websites and blocks suspicious access to Naver's services.

"In order to more actively cope with the infringement of intellectual rights, we are reviewing lawsuits against operators of such websites in cooperation with our artists," Naver said. "We also plan to take robust legal action against other websites that illegally post our comics."

Naver said the South Korean online comic industry suffered losses estimated at 200 billion won (US$187.3 million) last year due to piracy.