This image shows devices that were seized by police as part of their investigation into the hacking of built-in home cameras, Dec. 20. Yonhap

A hacker in his 30s was arrested on charges of infiltrating built-in home cameras at over 600 different apartment complexes and distributing recorded footage, police said Tuesday.

In Korea, it is common for internet-connected home security devices with cameras to be installed in apartment complexes. A wall-pad device, which is attached to the wall, can activate other devices inside the house.

The hacker, only identified by his surname Lee, is under suspicion of hacking wall-pad devices of more than 400,000 households in 638 different apartment complexes between August and November of last year, according to the National Police Agency (NPA).

Lee is known as a cybersecurity expert, the NPA said.

An investigation began after a series of thumbnail preview images of what appear to be people inside local apartments appeared on a dark web website that is inaccessible by regular web browsers.

Some of the video and image files secured by the NPA contain sexually explicit and intimate material, officers said.

Lee has denied the allegations, saying that he had provided such files in an attempt prove the need for better smart home security, police said. The NPA, however, found evidence that Lee had attempted to sell the files. (Yonhap)