The fallout from an alleged widespread hack of major tech firms has reached the U.S. telecommunications market. Following Bloomberg’s blockbuster report last week that detailed how China’s intelligence services planted malicious chips in server motherboards used in data centers operated by Apple, Amazon and many others, a security expert has come forward alleging that a major U.S. telecommunications company discovered manipulated hardware in its network and removed it in August.

Yossi Appleboum, a former Israeli intelligence officer and co-CEO of Sepio Systems, told Bloomberg that his firm was hired to “scan several large data centers belonging to the telecommunications company.” Bloomberg declined to name the company because of a nondisclosure agreement between Appleboum and the telecom company in question. The implant was discovered on an Ethernet connector used on a motherboard developed by Supermicro, according to Bloomberg.

The computer and infrastructure vendor strongly refuted the latest claims. “We still have no knowledge of any unauthorized components and have not been informed by any customer that such components have been found,” the company wrote in response to Bloomberg’s reporting.