Amid an ongoing row between Huawei and the US, evolving around Washington’s allegations that the Chinese tech giant poses a security threat because of its ties with Beijing, it turns out that a UK-based subsidiary of a Chinese company is part of the supply chain for Lockheed Martin’s fighters, flown by the Americans and its allies.

England-based Exception PCB (which stands for printed circuit boards), whose parent company is China’s Shenzhen Fastprint, produces circuit boards for the US-UK next-generation F-35 fighter, the British broadcaster Sky reports, citing publicity materials from the UK Ministry of Defence (MoD).

Among other things, its March publication Small and Medium-Sized Enterprise (SME) Action Plan specifically mentioned that Exception PCB is part of the F-35 supply chain.

"Gloucestershire-based Exception PCB manufactures the circuit boards that control many of the F-35's core capabilities”, the document reads.

Another publication is a news article, dating back to last November that praised the Chinese-owned firm's F-35 credentials. It said that its staffers "manufactured the circuit boards that control many of the F-35's core capabilities, including its engines, lighting, fuel and navigation systems".

However, as the report says there was no mention of the company’s relationship to the Chinese-based enterprise.

Shenzhen Fastprint bought the British company in 2013. Interestingly enough, Exception PCB is not only involved in the F-35 supply chain but also in manufacturing the Eurofighter Typhoon, Lockheed Martin’s F-16 and the Apache attack helicopter. It is also a third-tier supplier for the F-35 as the boards reach the jet through GE Aviation.

According to the company’s director Mike Devine, Exception PCB manufactures “bare circuit boards only in the UK for all of our aerospace and defence companies”, and have partnered with GE Aviation for decades. He insisted that they made everything possible to ensure that no Chinese national can access the F-35’s data.

"All data is secured on a separate internal server and access to data is protected by passwords, only accessible by a selected few, of which have been audited by GE”, he told Sky.

The MoD denied that there any risks linked to the firm’s Chinese ownership.

"Exception PCB produces bare circuit boards and as a result there are no risks associated with their product in the F-35 aircraft supply chain”, the ministry’s spokesman said, as cited by Sky.

For its part, Lockheed Martin has signalled that risks are still present although “all components on the F-35, are inspected repeatedly at each stage of manufacture”.

“Exception PCB has no visibility or access to any sensitive programme information and there is limited to no risk associated with their minimal role in the programme. Should Exception PCB be determined an unapproved source in the future, GE Aviation has alternate sources of supply that would ensure no impact to the programme”, its representative told the broadcaster.

These revelations come amid an escalation in the row between Chinese tech giant Huawei and the US. Washington has accused Huawei of exploiting cyberinfrastructure on behalf of China’s government, which the Shenzhen-based firm has adamantly denied.

Nevertheless, the Trump administration introduced a ban on the use of the Chinese company’s technology, barring US companies, including Google, from trading with the company without government approval. In addition, the White House is trying to make its European allies, including the UK, bar Huawei from building 5G infrastructure, threatening to curb intelligence cooperation with any country that allows Huawei equipment to be used on its own networks.