Choe Ryong-hae, a vice chairman of North Korea's ruling party, is believed to have played a role in the latest dismissal of the country's spy chief, a report by a South Korean state-run think tank said Sunday.

Kim Won-hong, 72, was fired as minister of state security in mid-January after a probe by the Workers' Party of Korea found his agency had abused authority.

Choe directed his party aides to conduct surveillance of Kim's ministry, inviting Kim's resentment, according to the report by the Institute for National Security Strategy.

"There was a source of friction between Choe and Kim. It is believed that Choe had played some role in (Kim Jong-un's) dismissal of the spy chief," the report said.

Choe is one of the close aides to the North Korean leader. But, to maintain his monolithic regime, Kim Jong-un does not allow any officials to exert excessive influence.

The report said that Choe has remained low-key since he was reinstated after being punished for his mishandling of a power plant project in late November 2015.

"To maintain his clout as a heavyweight, Choe needs a practical influence in appointment, but he is facing limitations, as Kim Jong-un has restricted his role (at the party) to prevent him from expanding his power base," the report added.

In another sign of a power struggle, Choe is said to be at odds with Hwang Pyong-so, director of the general political bureau of the Korean People's Army. Hwang is widely viewed as the No. 2 man in North Korea.

Hwang reported to the North's leader about the possibility that Choe could lead a revolt when he served as the director of the KPA's general political bureau in the past, it said.

"Choe is known to be seeking revenge against Hwang on the belief that the report led to his dismissal," it added.

Meanwhile, Hwang is seeking to prevent the dismissed spy chief and Kim Yong-chol, a key official handling inter-Korean affairs, from exerting an influence on the military.

"Among North Korean officials, there is a rumor that the relationship between Hwang and Kim Won-hong, the ex-state security minister, is like a dormant volcano whose timing for eruption is hard to predict," the report said.

Gen. Kim Yong-chol was appointed as the party secretary handling inter-Korean affairs, doubling as the head of the United Front Department at the ruling party. He previously led North Korea's reconnaissance bureau.

In the past, Kim Yong-chol had a good relationship with the spy chief, but his ties with Kim Won-hong and military official Hwang frayed as he sought to abuse his authority, the report added. (Yonhap)