Prosecutors requested an arrest warrant for the second time for a key figure in the 2013 sex and bribery scandal involving former Vice Justice Minister Kim Hak-ui.

A probe team in charge of the case said on Monday that they requested a local court to issue an arrest warrant for construction contractor Yoon Jung-cheon on charges of sexual assault, fraud and false accusation. 

It's the first time prosecutors have applied sexual assault charges against key suspects in the scandal. 

Yoon is accused of regularly sexually assaulting a woman and forcing her to provide sexual services to men, including the former vice minister who was arrested on bribery charges last week, from around 2006. 

The construction contractor is also accused of extorting over two billion won from people seeking permits for construction projects.