Police cracked a record 649 child pornography cases involving 310 underage victims in the first half of this year, the National Police Agency said Thursday.

The number of victims rose by 14.4 percent, while the number of busts increased 9.1 percent.

The police arrested or handed prosecutors cases on 455 suspects, up 9.4 percent, the NPA said.

Officials said all of the figures were the highest since 2000, when the agency began compiling comparable data, confirming an alarming increase in child pornography in recent years.

Cases of financial fraud also rose rapidly, with 193 cases coming to police attention between January and June, with damages totaling ¥1.87 billion, the NPA said.

The figures compare with the 33 cases that had come to their attention between February and June 2010, after the agency started tracking this statistic, and ¥94.13 million in damages. Financial products used in the frauds included corporate bonds, unlisted stocks and foreign currencies.

Of the 649 child pornography cases, 353 involved use of the Internet and 141 involved peer-to-peer file-sharing software, more than doubling the figure from the same period last year.

Major Internet service providers began blocking access to child porn websites in April.

File-sharing software is likely to be used to bypass the barriers erected by the providers by enabling users to send or receive image data without routing through computer servers, agency officials said.

"We see a serious situation in which images unbearable to watch are copied and distributed over the Internet, making the damage to children almost indefinite," a senior NPA said.

"Japan is a loophole for pedophiles from other countries with strict restrictions," an official with the Japan Committee for UNICEF said. "We must have a law to prohibit the possession of child pornographic data."

The NPA also said there were 153 other child abuse cases in the first half, with 162 victims and 163 suspects — and 14 kids died.