SEOUL, South Korea — The mayor of Seoul, South Korea, the country’s most powerful official after the president, was found dead by the police, hours after his daughter reported him missing, the authorities said Friday.

A Seoul police officer confirmed the discovery of Park Won-soon’s body in a hill in northern Seoul, but said he could offer no further detail until there was a formal announcement.

His disappearance came a day after a secretary in the mayor’s office told the police that he had been sexually harassing her since 2017, two Seoul television stations reported, attributing the information to unidentified police sources.

Mr. Park, 64, canceled his official schedule for Thursday and called in sick to City Hall. His daughter told the police that he had left home after leaving a cryptic, “will-like message,” according to Yonhap, the national news agency, which cited an anonymous police source.

When Mr. Park had not returned home after five hours, his daughter called the police.

The discovery of the body came after 580 police officers and emergency medical workers, aided by police dogs, searched the hills in northern Seoul.

The mayor of Seoul, a city of 10 million, is considered the second most powerful elected official in South Korea after the president. Mr. Park, who was serving his third term, had often been named as a possible candidate to replace President Moon Jae-in, whose single five-year term is set to end in 2022.

Mr. Park had been the mayor of Seoul since 2011. His latest term had been scheduled to end in 2022.

Before becoming mayor, Mr. Park was a prominent human rights attorney who founded the country’s most influential civil rights group.

As a lawyer, he won several major cases, including South Korea’s first sexual harassment conviction. He also campaigned for the rights of so-called comfort women, Korean sex slaves who were lured or forced to work in brothels for the Japanese army during World War II.