The police will continue to thoroughly investigate the opinion rigging scandal involving a former ruling party lawmaker, the country's police chief said Monday, hours after the parliament decided to appoint an independent counsel to look into the scandal.

"The police are somewhat ashamed in that the investigation should have been ended by the police but will now lead to the appointment of a special counsel. We will continue on with the investigation until the launch of the special counsel," National Police Agency Commissioner Lee Cheol-seong said in a meeting with reporters.

The remarks came shortly after the National Assembly passed a proposal to appoint a special prosecutor to investigate the opinion rigging scandal that the main opposition Liberty Korea Party claims may have led to the election of President Moon Jae-in.

A local blogger, known by his nickname Druking, is suspected of manipulating comments on Internet news stories in an effort to sway public opinion in favor of the ruling Democratic Party and President Moon.