Norwegian Supreme Court Receives Legal Filing with Fabricated Citations Allegedly Generated by AI Tool

In the first quarter of 2024, Norway's Supreme Court received a legal brief containing AI hallucinations - fabricated information that did not exist. The brief was submitted in connection with an appeal over a procedural question in a civil case and contained both laws and preparatory works that simply did not exist, according to Supreme Court Chief Justice Toril Marie Øie. The fabricated sources were discovered internally when the appeal was reviewed at the Supreme Court. Court researchers who prepare cases for Supreme Court treatment routinely review the central legal sources referenced in briefs from parties. When the researcher tried to find these sources, it turned out that the sources did not exist - the lawyer had simply not checked the AI-generated sources before submitting the brief. This represents the first time the hallucination problem has come to a head in Norway's Supreme Court, though similar incidents have occurred in US courts and other Norwegian contexts. The Supreme Court took up the matter with the responsible lawyer but did not impose sanctions in this case, though they indicated sanctions could be considered for future incidents. The court has updated their lawyer guidance to include specific warnings about AI hallucinations and requirements for quality control.