It is unclear if Lee took his own life, but police received a report the 48-year-old had left home after writing a suicide note.

South Korean actor Lee Sun-kyun, best known for his role in the Oscar-winning film “Parasite”, was found dead in a car in Seoul on Wednesday, police said, after weeks of an intense investigation into his alleged drug use.

Police said in a statement they had received a missing person report from Lee’s manager that the actor had left home, leaving an apparent suicide note. In their search for Lee, they found him in what they believed was an unconscious state in a car at a park in central Seoul.

Emergency officers later confirmed Lee was dead, according to Seoul’s Seongbuk police station. It is unclear if the 48-year-old took his own life.

Lee – who rose to international fame for his role as Park Dong-ik, the father of the wealthy Park family, in “Parasite” – had faced investigation over accusations of illegal drug use amid a government crackdown in which police questioned him three times, with one session running 19 hours over the weekend.

The Yonhap news agency reported the popular actor was suspected of taking drugs at the residence of a bar hostess. Lee had said that though he had taken what the hostess had given him, he had not known they were illicit drugs.

The hostess had reportedly told the police that Lee used drugs at her home multiple times – something he denied. He had earlier requested through his lawyer to take a lie detector test.

His drug tests had returned negative or inconclusive results, the report added.

Police said they regretted that Lee had died in the midst of investigations, but noted the investigation was “conducted with [his] consent”, News1 Korea reported.

“There is no way to contain the sorrow and despair. We respectfully ask that you refrain from spreading false facts based on speculation... so that [Lee’s] final journey will not be unfair,” Lee's agency, HODU&U Entertainment, said in a statement.

The investigation into Lee’s illegal drug use prompted extensive tabloid coverage, which caused considerable damage to his reputation. He was dropped from No Way Out, a mystery TV series that began shooting in October.

The actor, who was married to and had two sons with actress Jeon Hye-jin, had an acting career spanning more than 20 years.

Lee starred as the lead in dozens of films and TV shows, becoming a household name through the 2010s.

He won praise for his roles in the 2007 television series “Behind the White Tower,” the 2010 series “Pasta,” and the sci-fi thriller series “Dr. Brain,” for which he was nominated for an International Emmy Award

Infringements of South Korea’s tough drug laws can lead to six months in jail, or up to 14 years for repeat offenders and dealers. Consumption of marijuana carries prison sentences of up to five years.