China is accused of rigging a test of 5G mobile equipment in a campaign to discredit Western rivals of its embattled telecoms champion Huawei, The Sunday Telegraph can reveal.

Whitehall and industry sources said Beijing is feeding secret details of security vulnerabilities in new network kit to a team of IT specialists.

More than 100 computer security experts are conducting a security test of 5G equipment, from makers including Huawei and Western rivals Nokia and Ericsson, in which hacking techniques are used to check for weak spots. The ostensibly legitimate exercise is part of planning for 5G and its leap forward in speed and data capacity in the world’s biggest mobile market.

However, British officials and industry sources tracking the tests allege they are being rigged to defend Huawei. It is believed that vulnerabilities discovered by China’s secret state hackers have been passed to the 5G testers to ensure Nokia and Ericsson’s equipment is found to be unsecure.

Officials and Western telecoms executives held crisis meetings about the campaign last week.

Although knowledge of the effort is patchy, it is expected that testing will end around June 10, in time for Beijing to use the results to attempt to influence a crucial EU review of 5G security this summer. Two sources suggested China particularly intends to undermine cautionary advice on Huawei provided by British intelligence. Beijing’s hacking attack comes after a series of steps to turn China into what one corporate source has called a “hostile environment for non-Chinese telecoms firms”. Ericsson’s office in the Chinese capital was raided by state investigators last month over complaints of intellectual property infringement. It denies any wrongdoing.