Police are raiding Seongnam City Hall as part of their probe into suspicions that former Democratic Party presidential candidate Lee Jae-myung provided favors to firms after they made donations to Seongnam Football Club, which Lee owned while serving as the city’s mayor.

The Bundang Police Station in Gyeonggi Province sent 22 officers to city hall at 9:10 a.m. on Monday to comb through five divisions in the office building.

The raid came in response to a request for a supplementary investigation into the case by prosecutors from the Seongnam Branch of the Suwon District Prosecutors’ Office.

The police are trying to shed light on suspicions that, while serving as Seongnam mayor, Lee secured some 16 billion won in donations for the football club from major firms, including Doosan and Naver, between 2014 and 2016. In return, he is alleged to have provided favors to the donors by granting building permits.

Attention is being drawn to the latest probe as it comes after the police initially decided not to forward the case to the prosecution last September.