North Korea fired its state security minister last month, presumably over corruption, abuse of power and torture committed by his agency, the government of rival South Korea said Friday.

Jeong Joon Hee, spokesman for the Unification Ministry, said the sacking of Kim Won Hong, who had been seen as close to leader Kim Jong Un, might cause instability in the country's leadership by causing more fear in the ruling elite. North Korea has not said anything about Kim Wong Hong, and Jeong did not say how South Korea obtained the information.

There's a possibility that Kim Won Hong will face stronger punishment as the investigation into his actions is ongoing, Jeong said.

South Korea has a spotty record of tracking developments in North Korea as information about the secretive, authoritarian state is often impossible to confirm.

Since taking power in late 2011, Kim Jong Un has executed or purged a slew of high-level government officials in what the South Korean government has described as a "reign of terror."

The most spectacular among them was the 2013 execution of his uncle, Jang Song Thaek, once considered the second most powerful man in North Korea, for alleged treason. The South's government has said the North also executed a vice premier for education in 2016 for unspecified anti-revolutionary and factional acts, and a defense minister in 2015 for treason.

It was not clear if Kim Won Hong's reported sacking means he has been permanently removed from North Korea's leadership circle. Choe Ryong Hae, a close aide to Kim Jong Un, was believed to have been briefly banished to a rural collective farm for re-education in 2015, but he regained his political footing during a rare congress of the North's ruling Workers' Party last year.