Nikon disqualified the original winner of its Small World In Motion competition after learning the video used generative AI, Nikon said in a statement. The contest, running since 1975, offers a US$3,000 prize for the best microscope‑captured image or video.

The disqualified entry was produced by Ning Xu, an optical engineering researcher at Tsinghua University. The clip claimed to show cilia moving in the airways of a child with primary ciliary dyskinesia (PCD), magnified about 100 times.

Days after the winner was announced, microscopy experts questioned the clip’s realism on social media. Edward Phelps, an associate professor at Florida University, said the nuclei “do not behave as nuclei” and the cilia “appear from nowhere and do not match the known size.”

The wider microscopy community wrote an open letter to Nikon, urging an external review. The letter warned that a “potentially misleading portrayal of PCD is shaping public understanding of an already poorly understood rare disease,” and asked clinicians and researchers to sign the petition.

Nikon later announced Vietnamese researcher Nguyen Nam Nhat as the new winner for a video of a microscopic roundworm interacting with a single‑celled Dileptus, a entry that had originally placed second.

The incident highlights why clear competition rules and expert verification matter: without them, AI‑generated images can be mistaken for genuine observations, potentially confusing both scientists and the public about biological phenomena.