Actor Yoo Ah-in was questioned by police on Monday over allegations of habitual use of illegal drugs, according to investigators and reports. Police are also reportedly considering seeking an arrest warrant for Yoo.

Yoo, whose real name is Uhm Hong-sik, appeared at the Mapo-gu office of the Seoul Metropolitan Police Agency at around 9:20 a.m., flanked by a group of star lawyers specializing in drug offenses.

Yoo was originally supposed to appear before police on Friday, but he requested to postpone the date, citing that the schedule had been exposed to media. He did not respond to reporters' questions when entering the police office on Monday.

Yoo's lawyers include Park Sung-jin, a prosecutor-turned-lawyer known as an expert of drug-related cases for his long experience with drug investigations for the Supreme Prosecutors’ Office. Cha Sang-ho, and Ahn Hyo-jung, both former prosecutors who previously worked at Kim & Chang, the nation's largest law firm, also represent him.

Earlier this year, police launched an investigation into Yoo’s alleged drug use after it was revealed by the Ministry of Food and Drug Safety that he had received suspicious propofol prescriptions. Police found that he was administered propofol 73 times from Jan. 4 to Dec. 23, 2021.

Police had Yoo tested on Feb. 5 as he entered Incheon Airport from the United States. He has been banned from leaving the country since. A close examination by the National Forensic Service showed positive results for four drugs – cannabis from Yoo’s urine and propofol, cocaine and ketamine from his hair. Among them, propofol and ketamine are commonly used as sleep-inducing anesthesia for simple surgeries, but are also frequently misused for nonmedical purposes.

Police also have seized evidence from Yoo's home and plastic surgery clinics in Gangnam-gu and Yongsan-gu, both in Seoul, where Yoo was prescribed to have propofol administered. They summoned Yoo's acquaintances and managers as witnesses. Police are also expected to inquire into accomplices who may have used drugs together with Yoo.

Illegal use of propofol can result in up to 10 years in prison or a fine of up to 100 million won ($79,000) in Korea. First-time offenders, like Yoo would be, of recreational use of marijuana can be sentenced up to five years in prison or 50 million won in fines.

Regarding the propofol administration, Yoo has claimed that he requested sleep anesthesia because he feared needle injections while having treatment for a skin disease.