Police recorded 1,802 cases of Internet-related or cyber crimes during the first half of the year, up 11.8 percent over a year earlier and a record high for any first half, the National Police Agency said Thursday.

Offenses against the law barring illegal access surged to 265, up 33.8 percent, the NPA said. The NPA began collecting data in 2000.

"We will tighten our crackdown and strive to prevent damage by working with the Internet industry," the NPA said in releasing the report.

Cases of fraud abusing computer networks topped the list at 733 cases, up 9.1 percent, accounting for 40 percent of the total. The majority of such crimes were related to Internet auctions.

Prostitution involving minors under 18 acquainted through dating Web sites surged 18.2 percent to 169 cases, while offenses against the trademark law, such as submitting fake brand products to Internet auctions, saw a 112 percent increase to 106 cases.

The majority of offenses against the illegal access law involved accessing computer networks through other people's IDs and passwords. One case involved abetting such acts.

Police arrested or questioned 63 people in connection with illegal access cases. Teens and those in their 20s accounted for 36 of the total, of whom, the youngest offender was 14 years old.

Among cases involving stolen identification codes, 115 cases took advantage of lax security settings, such as passwords that can be easily guessed from user IDs, the NPA said.

The Internet fraud "phishing," in which users are tricked into entering their passwords into fake Web sites, totaled 102.

Meanwhile, police received 30,565 inquiries on cyber crimes in the first six months of the year, down 39.5 percent.

As the NPA opened in June last year a Web site providing information to fight Internet-related problems, the agency believes some of the questions were solved through the site.