SweepLED phone accessory spots hidden cameras in seconds, say KAIST researchers

In tests on 30 different objects, the device identified hidden cameras with a 94% success rate, the team reported. The accessory is placed over the phone's rear camera and, while video is recorded and the phone remains still, it turns its LEDs on and off and compares the different reflection patterns. Hidden camera lenses reflect light differently than standard reflective surfaces, allowing the AI to locate them.

"Hidden cameras pose a serious threat to personal safety and privacy in everyday spaces," Professor Jun Han of KAIST said. "This research is meaningful in that it combines low-cost smartphone-based hardware with AI analysis to present the possibility of a practical detection technology that even non-experts can use."

Earlier detection devices required users to manually look for "bright spots" produced by camera lenses. SweepLED is designed to be more efficient and to detect cameras concealed in a variety of objects, such as clocks or mirrors.

The KAIST team estimated the manufacturing cost of SweepLED at about $7 (roughly £5 or AU$10). The work has been presented at the ACM MobiSys 2026 conference and published online, but no release date has been announced.