U.S. law-enforcement agencies have been secretly embedding location-tracking devices in select shipments of advanced artificial-intelligence chips to detect and document attempts to divert the hardware to China, two people with direct knowledge of the tactic told Reuters. Trackers have been discovered in servers shipped by Dell and Super Micro that contain GPUs from Nvidia and AMD, the sources said. In a 2024 consignment, investigators used both smartphone-sized tags affixed to shipping cartons and smaller units concealed inside server chassis. The operation is run by the Commerce Department’s Bureau of Industry and Security, with support from Homeland Security Investigations and the FBI, and is limited to high-risk consignments under active investigation. Officials hope the data will bolster criminal cases against exporters who breach U.S. controls introduced in 2022 to curb Beijing’s access to cutting-edge semiconductors. Dell said it is "not aware of a U.S. government initiative" involving trackers; Super Micro declined to discuss its security practices, and Nvidia and AMD did not comment. China’s foreign ministry had no immediate response, but Beijing has repeatedly criticised Washington’s chip curbs, while U.S. lawmakers debate mandating built-in location verification in future shipments.