Mayor Park Won-soon’s body was found at Mt Bugak in northern Seoul around midnight after a search involving hundreds of police, the Seoul Metropolitan Police Agency said.
It did not give a cause of death. There was no sign of foul play although a detailed investigation would be needed, police official Choi Ik-soo told reporters.
The Yonhap news agency said a former secretary of Park had filed a complaint on Wednesday over alleged incidents of sexual harassment.
Choi said an investigation was under way after a criminal complaint had been lodged against Park, without elaborating.
Park’s daughter reported the mayor missing at 5:17 p.m. (0817 GMT) on Thursday, police said. Yonhap news agency reported that she also told police he had left a message “like a will”.
The former human rights activist and lawyer left the mayor’s official residence at around 10:40 a.m. on Thursday, wearing a black hat and a backpack, having cancelled meetings scheduled for the day, police said.
Police found his body after an hours-long search involving hundreds of officers using drones and dogs in one of the most mountainous parts of Seoul, just a few minutes from the heart of the city of nearly 10 million people.
About three hours later, his body was brought out of the woods by forensic officers, according to a Reuters photographer at the scene. Media gathered later outside Seoul National University Hospital, where his funeral was expected to begin.
Campaigner for women's causes
As Seoul mayor since 2011, Park was instrumental in its response to the coronavirus pandemic. He also played a vocal role in massive candlelight demonstrations that contributed to the ousting of former President Park Geun-hye in 2017.
He was also an outspoken advocate of women’s rights and gender equality, and was seen as a potential presidential hopeful for the liberals in 2022 elections.
As a lawyer in the 1990s, he won one of South Korea’s earliest cases on sexual harassment, and strongly advocated for the cause of “comfort women” who were forced to work in Japan’s wartime military brothels before and during World War Two.
Park also praised women for their courage after a series of women accused powerful politicians and policymakers of sexual wrongdoings amid the #MeToo movement in 2018.
“The resolve of individual heroines is not enough. I think we need social solidarity,” he said at the time.
Oh Keo-don, the former mayor of Busan, South Korea’s second-largest city, and another major player in liberal politics, stepped down in April after acknowledging unnecessary physical contact with a female staffer.