A South Korean man who was doing missionary work in the city of Dandong in China’s Lianoning Province was found to have died last month.

According to the South Korean consulate general in Shenyang Thursday, the 46-year-old man, identified only by his surname Han, suddenly collapsed while waiting for a cab in front of a department store in Dandong around seven p.m. on August 21st. He died despite being swiftly transported to the hospital.

At the time he collapsed, Han had froth in his mouth, raising the possibility he was poisoned. However, autopsy results found no traces of toxic materials in his body.

Han reportedly did not suffer from any chronic diseases before his death.

Chinese security officials proposed to Han’s bereaved family members that a more thorough autopsy be carried out to find out the exact cause of Han’s death. But his family refused the proposal and Han’s body was cremated last Friday and his remains were transported to South Korea.