The mayor of South Korea’s capital city has vanished amid sexual harassment allegations and after giving his daughter a message she described as sounding like a will, police have said.

Police said they are looking for Seoul mayor Park Won-soon near a small hill in the city’s Sungbuk neighbourhood, where his mobile phone signal was last detected.

They said the phone is currently switched off.

South Korea Seoul Mayor Missing
Police officers search for missing Seoul mayor Park Won-soon (Kim Ju-sung/Yonhap/AP)

His daughter called police on Thursday afternoon and said her father had given her “a will-like” verbal message before leaving their home about 4-5 hours earlier.

She did not explain the contents of the message, an officer at the Seoul Metropolitan Police Agency said.

His daughter said she decided to call police because she could not reach her father on the phone, the officer said.

About 700 officers, three drones and four police dogs were mobilised in the search, according to police.

South Korea Seoul Mayor Missing
Police officers stand guard in front of the official residence of Seoul mayor Park Won-soon (Lee Jin-man/AP)

Kim Ji-hyeong, a Seoul Metropolitan Government official, said Mr Park did not show up for work on Thursday for unspecified reasons and had cancelled all of his schedule, including a meeting with a presidential official at his Seoul City Hall office.

The Seoul-based SBS television network reported one of Mr Park’s secretaries lodged a complaint with police on Wednesday night over alleged sexual harassment, such as unwanted physical contact, that began in 2017.

The SBS report said the secretary told police investigators that an unspecified number of other female employees at Seoul City Hall had suffered similar sexual harassment by Mr Park.

MBC television carried a similar report.

Both the Seoul Metropolitan Police Agency and Mr Park’s office said they could not confirm the reports.

Mr Park, a long-time civic activist and human rights lawyer, was elected Seoul mayor in 2011.

He became the city’s first mayor to be voted into a third term in June last year.

A member of president Moon Jae-in’s Democratic Party, he has been considered a potential presidential candidate in the 2022 elections.