Prosecutors in South Korea are reportedly investigating the younger sister of North Korean dictator Kim Jong Un for blowing up a joint liaison office close to the demilitarized zone border in June.

The unprecedented — and mostly symbolic — probe of Kim Yo Jong  — who has made a rapid rise in her brother’s regime, becoming his most senior aide — and Army Gen. Pak Jong Chon  came after a South Korean lawyer filed a criminal complaint, the Yonhap news agency reported Thursday.

The North’s military blew up the building in Kaesong on June 16 — three days after Kim Yo Jong warned of a demolition.

Seoul lawyer Lee Kyung Jae filed a complaint July 8, and the case was assigned to the office's public investigation division Monday, the news outlet reported, noting, however, it’s nearly impossible for Seoul prosecutors to punish the North Korean officials— and prosecutors may choose to drop the charges. 

"It is difficult to arrest Kim and Pak and bring them to justice, but an investigation can be conducted,” he said, the news agency reported. “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.”

The explosion of the inter-Korean liaison office is close to a declaration of war because it’s a pseudo-diplomatic mission, Lee said.

Lee told the news agency intentional destruction of state property can carry a 10-year jail term even under North Korean law.

The destruction of the liaison office reflected deteriorating relations on the Korean peninsula, despite the recent detente between Pyongyang, Seoul and Washington, D.C. in recent years.

Observers have speculated Kim Jong Un may end the testing freeze or order other significant weapon tests in the run up to the U.S. presidential election, Newsweek reported.

• Pompeo Downplays Possibility of Summit with North Korea
• North Korea Says it Has No Plans for Talks with US