Fake News Court: A Multi-Agent Adversarial Framework for Robust Detection of LLM-Generated Fake News

Mengyao Peng, Hongyan Gu, Yiping Ma, Shiyu Hu, Xinli Huang


Abstract
Large language models (LLMs) have achieved remarkable success across many domains, yet their generative capabilities have been misused to produce highly realistic fake news that threatens social stability. However, the main existing detection methods, including small language model (SLM)-based approaches and LLM-based detectors, exhibit substantial performance degradation on LLM-generated content, reflecting a lack of robustness. SLM-based detectors rely heavily on fixed data distributions and shallow textual cues, while LLM-based detectors depend on prompt-based inference, making them sensitive to prompting and vulnerable to LLM hallucinations. To address this challenge, we propose Fake News Court (FNC), a robust multi-agent adversarial framework that integrates the complementary strengths of LLM and SLM for detecting LLM-generated fake news. FNC adopts an adversarial learning paradigm in which a quality-controlled generator produces diverse and challenging fake news, while a hybrid detector combines multi-dimensional LLM-based agent reasoning with an SLM-based classifier to ensure stable decisions. Extensive experiments show that FNC achieves an overall accuracy improvement of approximately 6% over competitive baselines on LLM-generated fake news, confirming its robustness.
Anthology ID:
2026.emnlp-main.2022
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
46053–46063
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2022/
DOI:
Bibkey:
Cite (ACL):
Mengyao Peng, Hongyan Gu, Yiping Ma, Shiyu Hu, and Xinli Huang. 2026. Fake News Court: A Multi-Agent Adversarial Framework for Robust Detection of LLM-Generated Fake News. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 46053–46063, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Fake News Court: A Multi-Agent Adversarial Framework for Robust Detection of LLM-Generated Fake News (Peng et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-main.2022.pdf