Chinese authorities are posing an espionage threat to British businesses, MI5 chief Jonathan Evans has reportedly warned.
The head of Britain's domestic intelligence service has sent a letter to 300 senior business figures warning them of the web-based danger from China, the Times newspaper reports.
It claims to have seen a copy of the message secretly distributed by Mr Evans warning against "electronic espionage attack" from "Chinese state organisations".
An access-limited summary of the letter on the Centre for the Protection of the National Infrastructure's website is quoted by the newspaper as saying the letter highlights "the need to ensure management of the risks involved" in working with China.
"The director general's concerns about the possible damage to UK business resulting from electronic attack sponsored by Chinese state organisations and the fact that the attacks are designed to defeat best-practice IT security systems" are also flagged up by the summary.
According to reports British businesses are coming under attack from China more and more frequently, with attempts to hack Whitehall passwords and the use of 'custom Trojans' noted as being on the rise.
A spokesperson said the Home Office did not comment on private communications.