Police have launched an internal investigation into 13 lawmakers, including a dozen from the main opposition People Power Party, over allegations of illegal real estate speculation directed at them or their family. 

The National Office of Investigation(NOI) under the National Police Agency said that it received a request from the Anti-Corruption and Civil Rights Commission to investigate the lawmakers on Thursday, and assigned the cases to respective regional police agencies earlier on Friday. 

The state anti-corruption watchdog raised the suspicions early this week following a two-month probe. 

With regional police bodies to probe cases that fall under their jurisdiction, the Sejong Police Agency will look into the case involving PPP lawmaker Yun Hee-suk, whose father had bought land in the administrative city. 

The case involving the wife of lawmaker Kim Eui-kyeom of the minor-progressive Open Minjoo Party regarding her real estate investment in southern Seoul will be dealt with by the Seoul Police Agency. 

An NOI official said if more suspicions are established, internal inspections will be turned into official investigations.