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The investigation into the audio file involving the late actress Kim Sae-ron and actor Kim Soo-hyun has taken a new turn. On December 15, 2025, several South Korean media outlets revealed that the National Forensic Service (NFS / National Forensic Service) concluded that it is impossible to determine whether the famous soundtrack broadcast by Garosero was manipulated or generated by artificial intelligence: «Determining whether the audio file had been manipulated by AI was deemed “undetermined (판정 불가)” due to technical limitations."
This statement comes as the debate over the authenticity of this recording has been fueling controversy for months, pitting Kim Sae-ron's family against the YouTuber. Kim Se-ui (gaseyeon) to Kim Soo-hyun, who strongly denies the accusations and has brought forth numerous pieces of evidence to defend himself all this time.
The NFS concludes that it is impossible to judge the use of AI
According to Gangnam police, the scientific laboratory submitted its report last month: current analysis capabilities do not allow for determining whether the voice in the file was generated or modified by AI. This technical limitation comes at a time when the recording (which we now know was not the original that was sent to the police), supposedly revealing a relationship between Kim Soo-hyun and Kim Sae-ron when she was a minor, has been circulating for several months. This conclusion is disappointing, as it was widely expected and is in line with the entire nine-month investigation, raising questions about the competence of the Korean police and justice system in cases involving AI. It also comes as a surprise, given that an independent firm had determined that the audio was fake within a few days, months ago.
Kim Soo-hyun's lawyer responded a few minutes after the announcement: «Ladies and gentlemen. The age of AI has arrived, and now no one will ensure your safety. Do not trust the government. The National Forensic Service cannot distinguish your voice from that of an AI. Take your own protective measures.»
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Kho Sang-rock, Kim Soo-hyun's legal representative, also continued: «The police were unable to obtain the original file lasting more than an hour that Kim Se-eui claimed to have initially. No, they didn't. Without the original and with an informant who has disappeared, it is of course worthless as evidence. If they had obtained that original file of over an hour, they would probably have been able to find sufficient evidence of tampering.»
The actor, represented by the law firm LKB & Partners, maintains that the file is an AI-generated montage, calling the recording a «falsified version.» His legal team had filed a complaint against Kim Se-ui for defamation via communication networks, under South Korean law.
Meanwhile, the police are conducting a thorough digital analysis of the seized devices, including the cell phone and tablet belonging to the head of Gaseyeon, to determine whether or not the content relayed constitutes a misinformation (But how many months after this content was shared, what remains on this phone? That is the question).
Kim Sae-ron's family, represented by lawyer Boo Ji-seok, made the audio file public at a press conference on May 7. In particular, the audio file contained the phrase, «I feel like I've been used since middle school,» which became central to the accusations.
Police announce that the investigation into Gaseyeon is coming to an end
Earlier on December 15, the Seoul Metropolitan Police Commissioner, Park Jeong-bo, indicated during a press briefing that the investigations against the head of Gaseyeon are in their final stages. According to him, 2 teams are working on the case: «The interviews are complete, and we are currently analyzing all the data collected,» he said. He added that the police have already received the results of the computer analysis: «The forensic team has submitted its findings, and we are in the process of finalizing the investigation. After a complete review of the evidence, a conclusion will be announced shortly.»
The case gained momentum in March when Kim Sae-ron's family accused Kim Soo-hyun, claiming that the two had been in a relationship since 2016, when the actress was 15 years old, and that the relationship had lasted six years. Kim Soo-hyun immediately denied the accusations, claiming that Gaseyeon had used AI deep voice technology to imitate Kim Sae-ron's voice. The actor responded by filing a complaint for false accusation (무고) against Kim Se-ui and certain members of the young actress's family.
Since then, numerous twists and turns have revealed that’none of the «evidence» announced by the family have in fact been provided to the police, that Kim Se-ui (Garosero) is involved in some twenty complaints for defamation, but the slowness of the investigation and the inability to reach conclusions, when internet users are already convinced of the ins and outs of the case, raises the question of what is really going on behind the scenes to prevent it from being resolved. The comments under the Korean articles are revealing of the mindset of internet users:
«If that's the case, what's the point of the National Forensic Service? 😂»
«Is this the standard of the Korea National Forensic Service? Is this really the expected result for this recording that has been kept for months? Haha...»
«How serious was the tampering that it was impossible to prove? How come the National Forensic Service didn't reveal it? Even editorials say it only takes three days. This is the height of incompetence and a global disgrace.»
«Is our country really so technologically backward? The Gangnam Police Station and the National Forensic Service were simply trying to mislead the public. Who is pulling Ga Se-yeon's strings?»
Visit final conclusion of the police investigation, announced as imminent, could determine the outcome of this case, which has been rocking the Korean entertainment industry for nearly a year.
Response from attorney Kho Sang-rock
Kim Soo-hyun's legal representative responded further to this announcement via a post YouTube Here is the translation:
«Several journalists contacted me by phone today. To avoid repetition, I would like to summarize the key points of my response.
Regarding the audio recording presented as Kim Sae-ron's voice, the fact that the National Forensic Service concluded that it was «impossible to determine» whether it had been manipulated by AI does not in any way mean that Kim Se-ui's dissemination of false information can be considered non-criminal.
From the outset, the police never got their hands on the «audio file lasting over an hour» that Kim Se-ui claimed to have. The only material sent to the National Forensic Service for analysis was limited to a few minutes of audio excerpts broadcast by Kim Se-ui during that day's press conference.
Even without revisiting the fact that the alleged assault on the informant was pure fiction, the absence of the purported one-hour original file and the sheer impossibility of identifying or locating the informant are sufficient to rule out any possibility that these few minutes of excerpts could be recognized as the genuine voice of the deceased.
I firmly believe that there is no realistic possibility that the police will conclude that this partial recording is the authentic voice of Kim Sae-ron and announce such a conclusion as the official result of their investigation.
Furthermore, even before obtaining the original file from the informant, Kim Se-ui hastily called a press conference, broadcast these audio clips to the entire nation, and categorically asserted that they were indeed the actual voice of the deceased, thereby spreading false information.
The justification given for holding this emergency press conference, even though the original file had not been secured or verified, was based on allegations of assault and death threats against the whistleblower.
All these claims were disproved in real time, and the police are well aware of this. To date, no police officer has actually believed the veracity of the assault allegedly suffered by the informant.
Nevertheless, I find it deeply suspicious that the police made no serious effort immediately after the press conference to identify the informant and recover the original file.
This is all the more concerning given that not only actor Kim Soo-hyun, but also journalist Kang Kyung-yoon and myself filed criminal complaints immediately after the press conference and repeatedly urged the police to act quickly.
What is largely unknown today is that the press conference did not focus solely on the recording allegedly linked to Kim Sae-ron. Several other audio files were released, involving Lee Jin-ho, Kang Yong-seok, individuals linked to lawyer Kho Sang-rock, and a so-called «white wife,» among others.
However, it appears that none of these other recordings have been subjected to forensic analysis. I cannot help but wonder about this complete lack of action.
Regarding the recording attributed to Kim Sae-ron, if an original file lasting more than an hour had actually existed and been recovered, it is highly likely that traces of manipulation would have been detected. The most plausible conclusion is that this original one-hour file never existed.
If the police had made reasonable efforts from the outset to identify the informant and obtain the original file, the situation would have been radically different.
Even if the informant could not have been apprehended, it would not have taken long to conclude that he had fled and that verification of the original file was impossible.
At this stage, the police could have, and should have, considered these elements alone as serious evidence of fabrication and accelerated the investigation accordingly.
But she didn't.
Instead, it took three months after the press conference for the police to finally receive, without any original files, only a partial excerpt of the audio broadcast by Kim Se-ui and lawyer Bu Ji-seok at the press conference, and forward it to the National Forensic Service for analysis. It then took another four months to obtain the results.
And as I warned him two months ago, the verdict was, unsurprisingly, «inconclusive.».
I find that completely incomprehensible.
Nevertheless, I still hope that the final outcome of the investigation will be reasonable and convincing.
That being said, even when examining this case solely from the perspective of the investigation into this audio recording potentially manipulated by AI, it is difficult to deny that a new serious stain has been cast on the credibility of police investigations in the Republic of Korea.
Today, in particular, I feel a deep sense of shame towards my country.»
