Police said Tuesday they have closed a five-month investigation into allegations that late Seoul Mayor Park Won-soon sexually abused a former secretary, failing to reach a conclusion on the high-profile case.

In July, a municipal official who had formerly worked as a mayoral secretary filed a complaint with the police, accusing Park of having sexually harassed her over several years.

Two days later, Park was found dead in an apparent suicide on the hills of a Seoul mountain. He left a note saying "sorry" to everyone but did not elaborate on the sexual harassment case.

The Seoul Metropolitan Police Agency said it has wrapped up the case without indictment and will transfer the case to the prosecution, leaving prosecutors to determine whether Park's death was related to the complaint and to what extent the allegations took place.

The prosecution is separately looking into whether Park had found out about the complaint in advance and, if so, through what sources he secured the information.

"We looked into the submitted documents and called in the victim and witnesses, but since Park was found dead we plan to transfer the case to the prosecution without indictment according to the relevant law," an official said.

Police said they have called in 26 witnesses and five defendants, including those who worked at the metropolitan government's secretary office, for the probe.

The police, however, declined to elaborate on the findings from a forensic analysis of Park's mobile phone, citing the late mayor and his family's "honor."

Police said they also plan to send a relevant case, in which seven people including senior officials at the city government were accused of abetting the sexual abuse, to the prosecution due to insufficient evidence.

Regarding victimization of the former secretary in online space, the police said they have suggested the indictment of four people, including two soldiers, for causing secondary damage by leaving malicious online comments targeting the victim.

Six others were also advised to be indicted for posting a photo of a wrong person as the victim, while five were suspected of circulating a document titled "The Victim's Complaint."

Police said one person has been additionally booked and is under probe for releasing the name of the victim online. (Yonhap)