A Korean-Chinese pastor who previously managed the largest church in Changbai Korean Autonomous County, Jilin Province, was found dead last Saturday, a South Korean Christian media outlet reported Sunday.

Pastor Han Choong-ryeol left the church at 2 p.m. Saturday and was found on the Chinese side of the Changbai Mountain at 8 p.m. with knife and axe wounds in his neck.

Activists and local journalists suspect he was assassinated by North Korean agents.

Han in 1993 established the Changbai (Jangbaek) Church in the county, which borders the North Korean city of Hyesan via the Yalu river. The church has more than 300 believers, mostly Korean-Chinese, as it is the sole church in the area.

He has been widely known as a person overseeing the defection route via Hyesan, one of the main defection routes.

However, one activist said helping defectors, considering he started activities related to defectors decades ago was not the reason for his death.

“Since last year, U.S. organizations have started funding him to establish underground churches in North Korea,” Pastor Kim Hee-tae, president of the missionary organization North Korea Human Rights Mission, told NK News.

The church started dispatching deacons into North Korea last year, Kim said.

“Some of them were arrested by North Korean authorities and some were missing. The North Korean State Political Security Department is likely to have learned Han’s role,” Kim added.

A similar incident happened three years ago, in which South Korean citizen pastor Kim Chang-hwan was killed by a poison needle in Dandong, China.

“He was about to infiltrate to North Korea with a fake Chinese passport to build underground churches,” Kim said.

Greg Scarlatoiu, executive director at the Committee for Human Rights in North Korea (HRNK) said this kind of assassination against North Korean human rights activists is “nothing new.” He cited the case of former high-ranking North Korean official Hwang Jang-yop, who faced several attempts on his life after his 1997 defection.

Scarlatoiu, who heads a U.S.-based organization dedicated to exposing North Korean human rights violations,  said he himself underwent suspicious cyber attacks in recent days.

“My computer was turned on in the morning many times, with a document I received from Syrian human rights defenders opened,” Scarlatoiu told NK News.

Scarlatoiu said North Korea has geared up multiple layers of character assassination, particularly after the UN Commission of Inquiry report about North Korean human rights was released in early 2014.

While the Ministry of Unification said on Monday that the Chinese police administration is investigating this case, since Kim had Chinese citizenship, a Christian activist based in Seoul released a message of consolation.

“It is hard for me to speak without tears since he was our coworker, fellow warrior and friend,” Reverend Eric Foley, founder of Voice of Martyrs who personally knew Kim, told NK News.