Actor Kim Soo-hyun has escalated his legal battle against the controversial YouTube channel Garo Sero Research Institute, filing new criminal charges and a civil suit over its allegations that he dated the late actress Kim Sae-ron while she was a minor.

On Tuesday, Kim's agency Gold Medalist and law firm LKB & Partners announced they had filed a new complaint against Garo Sero operator Kim Se-eui under South Korea's anti-stalking law. The filing comes amid growing public scrutiny over messages and videos released by the channel, which claim to show the actor engaging in a romantic relationship with Kim Sae-ron as early as 2015-when she was 15 and he was 27.

"For nearly a month, Garo Sero has broadcast false claims about Mr. Kim on a near-daily basis, including private photographs, messages, and videos," the agency said in a statement. "We believe the only way to stop these cyber-harassment tactics is through thorough investigation and legal accountability."

The YouTube channel alleged in multiple videos that Kim and Kim Sae-ron had been in a six-year relationship beginning when she was a teenager, which ultimately led to her psychological distress and death. Gold Medalist refuted the timeline, insisting that while some of the content circulated online is real, it is being misrepresented.

Kim Soo-hyun's team confirmed that a now-viral video of Kim Sae-ron cooking dakbokkeumtang (spicy chicken stew) for the actor was filmed in June 2018, but asserted that they were not romantically involved at the time. "The video was taken at Mr. Kim's residence in Seongsu-dong during his military leave, in the presence of his family. The two were not in a relationship at that time," the statement said.

Kim Soo-hyun’s Agency Responds: 'Kim Sae-ron Was a Minor in 2018, But They Were Not Dating'
(Photo : Gold Medalist/Law Firm LKB & Partners)
Kim Soo-hyun’s Agency Responds: 'Kim Sae-ron Was a Minor in 2018, But They Were Not Dating'

The agency also acknowledged a KakaoTalk exchange from April 2018, in which Kim Sae-ron expressed disappointment about not hearing from Kim. Kim replied, "I'm sorry." His legal team maintained that the messages were exchanged during a military break, but the two did not meet, and they only began dating in the summer of 2019.

The firm challenged Garo Sero's characterization of the evidence, stating: "Every piece of so-called proof has been either misrepresented or manipulated. We are compiling a comprehensive rebuttal to reaffirm that no romantic relationship occurred while Kim Sae-ron was a minor."

On Monday, the Seoul Central District Court assigned Kim's civil defamation and damages suit against Garo Sero and the late actress's family to Civil Division 14 under Judge Jeong Ha-jeong. Although the actor had previously announced a claim of ₩120 billion ($89 million), court filings show a formal claim amount of ₩110 billion ($82 million).

The court action follows weeks of public controversy and media attention surrounding Kim's personal life. During a March 31 press conference, Kim Soo-hyun denied all allegations and pledged to pursue legal remedies against false accusations. His agency said it would continue to take "firm legal measures" against defamatory content moving forward.