Actor Lee Sun-kyun of the Oscar-winning film "Parasite" is undergoing police questioning for a third time on Saturday over drug use allegations.

Incheon Metropolitan Police Agency has been questioning Lee since 10 a.m. regarding suspicions he used marijuana and psychotropic drugs, which are controlled substances in Korea.

Speaking to reporters before entering the Agency's headquarters, Lee apologized for causing concern to the public. 

However, when asked by reporters whether he would admit to drug use or whether he continued to plead that he didn't know they were drugs, Lee only said that he would faithfully submit to the questioning.

Lee appeared twice before for questioning on October 28 and November 4.

The actor is accused of taking marijuana and ketamine on multiple occasions at the home of a bar hostess.