The US is investigating Bitmain Technologies, a Chinese manufacturer that dominates global Bitcoin mining hardware supply, over potential national security risks including espionage or sabotage threats from its specialized mining equipment.

The months-long probe, known as Operation Red Sunset, has intensified amid concerns over Bitmain devices operating near sensitive US military sites. US investigators are examining whether the company’s hardware could pose manipulation or surveillance risks.

Bitmain has denied any security issues with its products. The investigation reflects broader US concerns over Chinese-linked Bitcoin mining operations, particularly those with proximity to military bases and potential ties to the Chinese state.

A US congressman has called for a Treasury review of China-linked mining firms like Bitmain as trade tensions between the two nations continue to escalate. The scrutiny comes as the US examines various Chinese technology companies for potential national security implications.