The prosecution on Monday detained a former Democratic Party member who locked in an intelligence agent last year accused of conducting an online smear campaign against an opposition candidate during the presidential election.

The man, identified by his surname Chung, continued to defy the prosecution’s summonses, an official said.

The ruling Saenuri Party and a National Intelligence Service official surnamed Kim have filed complaints against him and other DP members who allegedly kept her from leaving her residence from Dec. 11-12.

They demanded her to hand over her laptop, claiming she was a member of an NIS team involved in election interference and posted negative online comments about opposition candidate Moon Jae-in.

The law requires government employees to remain neutral in elections.

The prosecution said they have already questioned other suspects except for Chung and will decide whether to seek arrest warrants against them later.

By Cho Chung-un (christory@heraldcorp.com)