Equipment and services provided by Chinese firm ZTE pose a national security risk in the UK, the National Cyber Security Centre (NCSC) has warned.
NCSC technical director Ian Levy has written to British telecoms firms warning them that ZTE poses a risk because it is state-run, and therefore subject to laws that could compromise the security of users.
According to the Financial Times, he told firms that new legislation now in place in China enable the one-party state's government to use "wide-ranging powers of compulsion" to influence individuals and companies.
Mr Levy added: "Mitigating the risk of external interference with equipment supplied by a particular vendor depends in significant part on telecommunications equipment being present from other vendors who are not subject to the same risk of external interference.”
Noting that the UK telecoms network already has a lot of equipment supplied by fellow Chinese manufacturer Huawei, he added: "Adding in new equipment and services from another Chinese supplier would render our existing mitigations ineffective."
It is certainly not the first time a government agency in the west has warned companies against using equipment supplied by ZTE. In 2012, a US Congress committee report claimed both ZTE and Huawei posed a threat to national security.
Indeed, the US has just announced a seven-year ban on American companies selling products and services to ZTE. According to the Guardian, this was in response to the sale by individuals of sensitive American electronics equipment to Iran and North Korea and the refusal of ZTE to act against individuals who had carried out these transactions. The company was fined $1.2 billion (£860 million) for the infraction.
ZTE has a partnership with BT, but the UK telecoms firm issued a statement insisting that it has a "robust testing regime" in place to maintain essential security.
Both the UK and US authorities have issued warnings in recent months of an ongoing cyber threat from Russia, which may have intensified amid the growing diplomatic tensions arising from the Salisbury poisoning incident.