An Internet hot line seeking tips on sites offering illegal information experienced a 75.3 percent surge in submissions in the first six months of the year, the National Police Agency said Thursday.

During the January-June period, the Internet Hotline Center received 18,542 reports of illegal information on websites, including child pornography and ads for banned drugs, the highest since it was set up in 2006, the NPA said.

The center received 5,441 reports about harmful information, including suicide pleas and offers to commit paid murder, up 53.9 percent, the NPA said.

The Tokyo-based center asked website operators to delete illegal information in 9,602 of the cases but was ignored in 2,014 of them, including 239 containing child porn, because it has no authority to enforce its requests, which are nonbinding.

According to reports from the center, police charged people in 226 cases, up 174 from the same period the previous year, including 117 cases that pertained to child porn.

Authorities fear repeated duplication of indecent images may inflict much more serious damage on children if left online for a long period of time.

The government has been preparing to have Internet service providers block access to child pornography based on tips to the center and other reports.