Taiwan Semiconductor Manufacturing Company said Tuesday it had discovered “unauthorized activities” of employees suspecting of stealing trade secrets related to its advanced computer chips.

Taiwan prosecutors arrested six people suspected of stealing trade secrets from Taiwan Semiconductor Manufacturing Co., opening an investigation into a potential breach of national security involving a global tech industry linchpin.

Taiwan has arrested six individuals in a major national security probe after chipmaking giant TSMC reported a suspected leak of proprietary 2-nanometer chip technology, the company’s most advanced semiconductor process to date.