An ethnic Korean clergyman with Chinese nationality was found dead in a northeastern Chinese town close to the North Korean border, a report by Yonhap said. The man was known to have supported North Korean defectors and his death has raised the question: was he murdered by North Korea?

The priest, identified only by his surname Han, was found dead Saturday, Yonhap reported, citing a North Korean watcher. Police officials in China have opened an investigation into his death. Han served at the Changbai Church in Changbai County, Jilin Province, which has a high population of Chaoxian people — ethnic Koreans living in China.

“Han had been active in supporting North Korean defectors,” the unidentified watcher said, according to Yonhap, adding: “Murder seems the most likely cause of his death.” However, the source denied having any concrete information linking North Korea to the death.

In April, 13 North Koreans working at a restaurant in China defected to South Korea, causing the already-tense relationship between the neighbors to become pricklier. Pyongyang claims that Seoul lured and abducted the workers, and demanded they be sent back immediately.

“We sternly denounce the group abduction of the citizens of the DPRK [Democratic People's Republic of Korea] as a hideous crime against its dignity and social system and the life and security of its citizens,” a statement, released early April by North Korea, said, adding: “The recent case of ‘group defection’ cooked up by the puppet group is a crucial provocation against the DPRK which can never be tolerated as it is an unbearable insult to the people of the DPRK.”

A report Tuesday also said that North Korea was ramping up security at its borders and was cracking down on the use of cell phones near the border in an effort to curb defections. The report added that Pyongyang increased the amount of barbed wire on the fences, set up surveillance cameras and planted mines along part of the Tumen River, which separates China and North Korea.

The Kim Jong Un regime has been accused by United Nations and other international organizations of conducting human rights abuses in the country, which are said to be a major cause for defections. A Yonhap report last month said about 29,000 people had defected to South Korea by the end of March 2016, and that the number was expected to cross 30,000 soon.

However, Pyongyang has denied the accusations of human rights abuses and condemned the reports by organizations critical of the regime.