NeurIPS, one of the world’s top academic AI conferences, accepted research papers with 100+ AI-hallucinated citations, new report claims
Hallucinated Citations Slip Past Peer Review at NeurIPS, Exposing AI's Double-Edged Sword in Academia In a stark irony for the field pioneering artificial intelligence, the prestigious NeurIPS conference has accepted and published research papers riddled with over 100 fabricated citations generated by AI models. Canadian startup GPTZero's analysis of more than 4,800 papers from NeurIPS 2025 revealed these "hallucinations"—fake references that evaded multiple layers of peer review—raising urgent questions about the integrity of AI-driven research workflows. NeurIPS, formally the Conference on Neural Information Processing Systems, stands as one of the crown jewels in machine learning academia. Held last month in San Diego, the 2025 edition drew a record 21,575 submissions, up over 220 percent from 2020, with a main track acceptance rate of just 24.52 percent. That means each accepted paper outcompeted roughly 15,000 others, undergoing scrutiny from three or more expert reviewers trained to spot flaws, including AI-generated errors. Yet GPTZero's audit, first detailed in a Fortune report, uncovered hundreds of bogus citations across at least 51 to 53 papers, marking the first documented case of such issues entering the official proceedings of a top-tier AI conference. GPTZero, founded in January 2023 and backed by a $10 million Series A in 2024, specializes in detecting AI misuse. Its Hallucination Check tool scans documents by cross-referencing every citation against the open web and academic databases like Google Scholar and arXiv. It verifies authors, titles, publication venues, and URLs, flagging mismatches or outright inventions. In the NeurIPS sweep of 4,841 accepted papers, the automated system identified suspects, which were then manually vetted by GPTZero's machine learning team to eliminate false positives. The result: over 100 confirmed hallucinations, ranging from fully fabricated entries—nonexistent authors, phony journal names, dead-end links—to subtler distortions where AI mashed up real papers with invented details, like adding five nonexistent co-authors to a legitimate reference. Edward Tian, GPTZero's cofounder and CEO, called this a "big moment" for the field. "These survived peer review and were published in the final conference proceedings," he told Fortune. Around half the affected papers showed signs of heavy AI involvement in their text, flagged with high probabilities of machine generation or hybrid human-AI authorship. But GPTZero emphasized the citations themselves as the core issue, distinct from broader AI detection debates plagued by false positives. Alex Cui, the company's CTO, explained how humans rarely make such specific blunders: "Sometimes, even when there is a match, you'll find that they added like five authors who don’t exist to a real paper." This isn't GPTZero's first rodeo. Just weeks prior, the firm spotted 50 hallucinated citations in papers under review for ICLR 2026, the International Conference on Learning Representations, set for April in Rio de Janeiro. Those slipped past initial reviewers but hadn't been accepted; ICLR has since enlisted GPTZero to screen future submissions. NeurIPS papers, by contrast, were already presented live and etched into the academic record. NeurIPS organizers acknowledged the findings to Fortune, noting that even if 1.1 percent of papers (a rough proportional estimate) carried incorrect references from LLM use, "the content of the papers themselves [is] not necessarily invalidated." Still, the conference prides itself on "rigorous scholarly publishing," with reviewers explicitly instructed to flag hallucinations. The numbers paint a nuanced picture. Across tens of thousands of citations in NeurIPS proceedings—each paper typically lists dozens—the 100 fakes represent a tiny fraction, statistically negligible per some critics. Papers from elite institutions like top U.S. universities and industry giants including Google were implicated, underscoring that no one is immune. GPTZero's methodology is cautious: it excludes simple typos, dead URLs from legitimate archival works, or missing page numbers, focusing on implausibly AI-like errors. Its false negative rate hovers near zero, catching 99 out of 100 issues, though flagging unfindable citations invites some false positives requiring human checks. Diving deeper into the technical implications, these hallucinations strike at the heart of scientific reproducibility, a perennial pain point in AI research. Modern machine learning papers often report results that are fiendishly hard to replicate due to stochastic training, hardware variances, or unpublished hyperparameters. Citations serve as the field's lifeline: they anchor claims to verifiable priors, enabling others to trace, test, and build upon concrete work. A hallucinated reference? It leads researchers down a dead end, eroding trust in the citation graph that underpins careers, funding, and progress. Large language models (LLMs) like those from OpenAI or Anthropic excel at pattern-matching but falter on grounded retrieval. When prompted to generate bibliographies, they "complete the pattern"—spinning plausible titles, DOIs, and venues from training data without external verification. This failure mode amplifies in high-stakes literature reviews, where authors lean on LLMs to accelerate sifting through exploding publication volumes. NeurIPS submissions ballooned amid this AI boom, straining reviewers who, ironically, may themselves use tools to cope. Reports suggest growing distrust, with some reviewers accused of AI-assisted skimming rather than deep reads. The fallout extends to citations as academic currency. H-indexes, impact factors, and tenure packets hinge on them; fabricated ones dilute the ecosystem, much like counterfeit money. NeurIPS and ICLR policies already deem hallucinations rejection-worthy, akin to plagiarism. Yet enforcement lags, as detectors aren't foolproof. GPTZero's tool offers a path forward: transparent, auditable checks integrated into submission portals, much like ICLR's pilot. Broader adoption could include mandatory disclosure of AI use in writing or citing, plus reviewer training on hallucination red flags. Looking ahead, this scandal accelerates a reckoning in AI academia. Conferences face mounting submissions—NeurIPS 2025's surge signals no end in sight—while LLMs permeate every stage from ideation to polishing. Will top venues mandate anti-hallucination scans? Expect more: tools like Perplexity or Elicit already aid verified retrieval, and blockchain-based citation ledgers could one day cryptographically prove provenance. GPTZero's report, while not invalidating the science, spotlights a vulnerability: the very tech advancing research now undermines its foundations. For NeurIPS, the prestige endures, but the episode injects humility. As Tian noted, it's an "escalation" from pre-publication slips to canonized errors. The field must evolve faster—verifying not just novelty, but veracity—or risk a hall of mirrors where even the mirrors lie. In the end, catching AI's fabrications may demand the one thing it can't fake: rigorous human oversight.