A former North Korean agent who has been living in South Korea since the 1960s has been arrested on charges of participating in a plot to assassinate Hwang Jang-yop, a high-level North Korean defector.

The Seoul Central District Prosecutors’ Office says the former agent, identified by his surname Han, was recruited by North Korean agents while trying to meet with his North Korean family in China in 2000. The prosecution said it appears Han reverted to spying for North Korea in return for the North Korean agents allowing him to meet with his family.

Han was reportedly attempting to find where Hwang is living in South Korea.

On Thursday, a South Korean court gave ten-year sentences to two North Koreans who were arrested in Seoul after their reported involvement in a plot to kill Hwang, who has been labeled a “traitor” by Pyongyang.