South Korean prosecutors have begun an investigation into North Korean leader Kim Jong-un's sister and the North's military chief on charges of blowing up an inter-Korean liaison office in Kaesong last month, officials said Thursday.

The unprecedented and symbolic probe into Kim Yo-jong, the sister now serving as the first vice department director of the ruling Workers' Party's Central Committee, and Army Gen. Pak Jong-chon, chief of the General Staff of the North Korean army, came after a South Korean lawyer filed a criminal complaint against them over the Kaesong office demolition in mid-June.

Seoul-based lawyer Lee Kyung-jae filed the complaint against the North Korean figures with the Seoul Central District Prosecutors Office on July 8, and the case was assigned to the office's public investigation division on Monday, according to the officials informed of the case.

North Korea destroyed the inter-Korean liaison office in its border city of Kaesong on June 16 apparently in anger over propaganda leaflets criticizing leader Kim, following Kim Yo-jong's warning of such a demolition in a statement issued on June 13.

The Seoul prosecution plans to review Lee's complaint before deciding whether to apply charges against Kim and Pak, the officials said.

It is virtually impossible for Seoul prosecutors to punish the North Korean officials, legal experts here said. The prosecutors may choose to drop the charges due to difficulties in evidence collection, they speculated. Even if the North Koreans were found guilty in a local court, there is no way to execute the verdict, they added.

Lee also admitted to the realistic limit but said he wanted to bring public attention to the North's act of destruction and inform the North Korean people of their leader's hypocrisy.

"It is difficult to arrest Kim and Pak and bring them to justice, but an investigation can be conducted. We should let 25 million North Koreans know about their ruling family's false image and hypocrisy, as well as about the legal order of our free democracy," Lee said.

He noted intentional destruction of state property can be punished with more than 10 years in prison or life imprisonment even under North Korean criminal law.

He also emphasized that under the Constitution, North Korea is under South Korea's jurisdiction.

The explosion is close to a declaration of war because the liaison office is a pseudo-diplomatic mission, he added.

On July 7, the Seoul Central District Court ordered Kim Jong-un and North Korea to compensate two former prisoners of war for forced labor during their captivity in the North.

It was the first time that a South Korean court has claimed its jurisdiction over North Korea and its people and issued a compensation order against them.

The ruling may affect several other cases against the North Korean leader currently pending at the prosecution office, including a complaint filed by conservative civic groups over his "crimes against humanity." (Yonhap)