Expert Witness: AI-Cloned Ad Voice Eerily Resembled Voice Actor Łukomski

The Regional Court in Warsaw heard testimony from a forensic voice analysis expert in a case that could set a precedent in Poland for protecting a person's voice from AI cloning. Forensic phonetics expert Tomasz Łach stated that the voice used in an online advertisement was eerily similar to that of professional voice-over artist Jarosław Łukomski, though he noted it was not Łukomski's natural voice.

The case concerns an online advertising campaign for home sewage treatment systems that, according to Łukomski, used an AI-generated voice sounding almost identical to his own. The voice-over artist says he never recorded the material, never consented to appear in the campaign, and received no payment for the commercial use of his recognizable voice.

First of all, that voice was saying something I never read - Jarosław Łukomski, voice-over artist, plaintiff in the case

What the Expert Said

A central element of the hearing was the opinion of court-appointed forensic voice analysis expert Tomasz Łach. Asked directly whether the voice in the advertisement belonged to Łukomski, he said it was eerily similar to the voice-over artist's voice, but stressed that it was not his natural voice, and that the signal data of the recordings differed noticeably from one another.

The court, however, ruled that the opinion needs to be supplemented. The key question the expert must answer in the next assessment concerns not only the technical similarity of the sound waves, but listener perception, whether an average viewer of the ad could recognize the voice as belonging to a specific, well-known person.

The court wants to obtain an opinion on whether an average listener would perceive this voice as the plaintiff's voice - Judge Sylwia Wit vel Wilk, Regional Court in Warsaw

A Gap in the Law

Legal experts point out that Polish law currently contains no provision directly addressing protection of a person's voice against digital imitation, since until now such regulation simply wasn't needed. Dr Damian Flisak of the law firm Lubasz i Wspólnicy notes that European legislation likewise provides no explicit protection of this kind.

In practice, Łukomski's lawyers must rely on provisions never originally designed for AI-related cases: Article 81 of Poland's Copyright Act, covering protection of a person's image, Article 23 of the Civil Code, which protects personal rights, GDPR provisions on the processing of personal data, and rules on unfair market practices, which may extend to deepfakes used in advertising.

A German Precedent

The Polish case is not an isolated one in Europe. In August 2025, the Berlin Regional Court ruled that using an AI-generated voice modeled on a dubbing actor's voice violated his personal rights, and awarded him 2,000 euros in damages for a single film. The court held that the decisive factor was whether the voice is publicly recognizable as belonging to a specific person, exactly the same criterion the Warsaw court is now examining.

What's Next

For Poland's community of voice-over artists, dubbing actors, and voice creators, the Łukomski case carries weight beyond a single lawsuit. Creative communities have for months been demanding clear regulations on consent for the use of a person's voice by AI systems, pointing to this very trial as an example of a legal gap that urgently needs to be closed.

The defendant company reportedly claimed it did not know the voice used belonged to a recognizable voice-over artist, and said it never intended to infringe anyone's rights, removing the ads immediately after receiving a cease-and-desist request. A final ruling, including the supplemented expert opinion, is expected following the hearing scheduled for August 21.