A priest who provided aid to North Korean defectors fleeing the oppressive country has been martyred by North Korean secret agents in northeast China.

According to a report from persecution watchdog Open Doors, Han Choong Yeol, 49, an ethnic Korean with Chinese citizenship, had helped North Korean refugees since 1993 by giving them food, medicine, clothing and other goods they needed for survival back in the isolated country.

Last weekend, Han, who was a priest at Changbai Church, in China's Jilin Province, left his home located on the Chinese side of the Sino-Korean border just after noon. When he didn't come back before 5 pm, a large search was set up, and around 8 pm, his lifeless body was found, visibly maimed by stab and axe wounds.

Choi Sung-yong, head of the civic organization Come Back Home, told local media on Monday that he heard from sources that "three North Korean agents came over [to Jilin Province] and killed the pastor, returning back to North Korea afterward."

People who worked with Han described him as "extremely passionate for North Koreans" who knew of the dangers associated with his work: In November 2014, a deacon of his church was kidnapped and never heard of again.

Han leaves behind a wife, a son and a daughter as well as the local 600-member church he pastored.

The Telegraph notes that Chinese authorities return refugees who are captured to North Korea, so human rights groups have set up networks of safe houses that defectors can use until they are able to cross a border to another country before traveling into South Korea.

"We have had reports of this sort of thing happening before and we have seen a sharp increase in the security on the border with China since Kim Jong-un came to power", Robert Park, a founding member of the Worldwide Coalition to Stop Genocide in North Korea and a former prisoner of North Korea told the outlet.

However, North Korean security agents regularly cross the border in search of defectors with the support of Chinese officials, who do little to protect their own citizens.

"American and South Korean citizens doing this sort of work in northeast China might be a little safer, but Chinese citizens are in danger because their own government does nothing to protect them", Park said.

Assisting defectors in northeast China has become so dangerous that several groups have suspended their operations, while other groups charge thousands of dollars per person to bring people out of the restricted country.

In North Korea, practicing Christianity is illegal; in fact, for the 14th consecutive year, the country topped Open Door USA's World Watch List of countries where believers face the most persecution.

"Christianity is not only seen as 'opium for the people,' as is normal for all communist states, it is also seen as deeply Western and despicable," reads the report.

"Christians try to hide their faith as far as possible to avoid arrest and being sent to labor camps with horrific conditions. Thus, one's Christian faith usually remains a well-protected secret, and most parents refrain from introducing their children to the Christian faith in order to make sure that nothing slips their tongue when they are asked."