"But I don't believe I was involved in any problematic behavior," he said, arguing that what he remembered is different from what she claimed had happened.

In a separate phone conversation with Yonhap News Agency, he said, "Resigning is to keep my honor. I will seek to set the facts straight." 

The alleged victim claimed in an interview with a local media outlet that the lawmaker had sexually harassed her in May 2008.

Min, currently in his third term as a lawmaker, had declared his bid to run in his party's race to select a candidate for the June Seoul mayoral election.

His resignation is another blow to the ruling party, which has seen some of its most prominent members become involved in sexual abuse allegations ahead of the June local elections.

This week, An Hee-jung stepped won as governor of the central South Chungcheong Province over allegations he had forceful sexual relations with a female secretary four times over the past eight months.

The fall from grace of An, who was widely thought to be a potential presidential candidate, is a major setback for the liberal ruling party three months ahead of gubernatorial and mayoral elections. The polls are being seen as a referendum on President Moon Jae-in's first year in office. (Yonhap)