A mourner pays his respects at the funeral hall of Seoul National University Hospital in Jongno-gu, Seoul, Sunday, at a memorial set up for Chang Ki-pyo, a pro-democracy and labor activist in the 1970s. (Yonhap)

Chang Ki-pyo, a prominent pro-democracy and labor activist in the 1970s, has died. He was 78.

Chang died of gallbladder cancer early Sunday at a hospital in Ilsan, Gyeonggi Province, according to his family.

Born in 1945 and enrolled at Seoul National University in 1966, Chang began actively campaigning for democracy and labor rights in 1970 in the wake of the self-immolation of Jeon Tae-il.

Jeon burned himself to death in 1970 in protest of brutal working conditions at a Seoul sewing factory.

Chang had been in jail for nine years under the notorious National Security Law.

However, Chang refused to receive compensation for the treatment he had undergone.

In a media interview in 2019, Chang said he did not receive compensation because he played a role as a "citizen and an intellectual."

Since 1989, Chang had created some minor political parties, but he never became a lawmaker.

President Yoon Suk Yeol mourned Chang's death. "Chang Ki-pyo was a true role model of the labor and democratization movement of our time. We will remember him," Yoon was quoted as saying by his spokesperson Jeong Hye-jeon.