The police raided Seongnam city government offices on Thursday as part of their investigation into allegations that then-Mayor Lee Jae-myung provided preferential treatment for an apartment construction project in Bundang District's Baekhyeon neighborhood.

The Gyeonggi Nambu Provincial Police Agency sent about ten investigators in the morning to begin the search and seizure of evidence at municipal offices handling urban planning and development as well as housing.

This comes after the police raided the homes of two key figures at the center of the allegations the previous day – Kim In-seob, Lee's former election camp chief when he ran for mayor in 2006, as well as the head of a real estate development company.

The allegations surround a construction project of over 12-hundred apartment units at the former site of the Korea Food Research Institute(KFRI) that started in 2015.

Seongnam city is suspected of making a rare move in approving the large-scale project as a semi-residential area when Lee was mayor, despite having twice rejected KFRI's request to change the land usage from a natural green area in 2014 to a residential area.

The Baekhyeon apartments were also initially promoted as a private rental project, but the rental ratio was later reduced to only ten percent, while over 11-hundred homes were converted to pre-sale housing.

The allegations were first raised by the now-ruling People Power Party and civic groups, after which the Board of Audit and Inspection(BAI) conducted an investigation. The BAI later requested that the prosecution open a case.